Why do the first 4 hexagrams of the Dui Palace share Gua Qi 4, while the last 4 change their Gua Qi number?

Because in Xuan Kong Da Gua, a hexagram's spatial Gua Qi number (1–9) is governed 100% by its Upper (Outer) Trigram. In the Jing Fang transformation sequence, the Pure Root, 1st Generation, 2nd Generation, and 3rd Generation only flip lines in the Lower (Inner) Trigram, preserving Dui ☱ on top (Gua Qi 4). In the 4th Generation, 5th Generation, Wandering Soul, and Returning Soul, the line changes move into the Upper Trigram, shifting their spatial Gua Qi while retaining their Dui Palace ancestral soul.

Which hexagrams in the Dui Group (Lake ☱ · Đoài Cung) are strongest for Period 9 (2024–2043)?

For Sitting Mountain, high terrain, and executive backing (Direct Spirit / Chinh Than), the crown jewel is #31 Trạch Sơn Hàm (澤山咸 ䷞), the 3rd-Generation Parent Hexagram carrying Star Period 9 at Khôn (208.125°–213.750°). For Main Gate, Water Mouth, and driveway intake (Indirect Spirit / Linh Than), the prime choice is #58 Đoài Vi Trạch (兌為澤 ䷹), the Pure Root Hexagram carrying Star Period 1 (forming 1+9=10 Sum-of-Ten with Period 9) at Tân – Tuất (283.125°–288.750°).

How do Sum of Ten (He Shi) and Difference of Five (He Sheng Cheng) work for the Dui Group (Lake ☱ · Đoài Cung)?

All 8 Upper-Dui compass hexagrams carry Gua Qi 4. They achieve Husband-Wife Sum-of-Ten (He Shi) when paired with Gen Group ☶ (Gua Qi 6 Water · 4 + 6 = 10), and achieve He Tu Generative Difference-of-Five (He Sheng Cheng) when paired with Qian Group ☰ (Gua Qi 9 Metal · 4 – 9 Allied Metal).

☱ XUAN KONG DA GUA · 8 TRIGRAM PALACES Gua Qi 4 · Yin Metal (He Tu 4–9 Allied Metal) • Early Heaven 2 / Later Heaven 7

Dui Group (Lake ☱ · Đoài Cung) in Xuan Kong Da Gua (兌宮八卦): 8 Palace Hexagrams, 384-Yao Degrees & Period 9 Mastery

Q: Which 8 hexagrams belong to the Dui Group (Lake ☱ · Đoài Cung) in Xuan Kong Da Gua?

In the Jing Fang 8-Palace lineage, the Dui Group (Lake ☱ · Đoài Cung) comprises #58 Đoài Vi Trạch (䷹), #47 Trạch Thủy Khốn (䷮), #45 Trạch Địa Tụy (䷬), #31 Trạch Sơn Hàm (䷞), #39 Thủy Sơn Kiển (䷦), #15 Địa Sơn Khiêm (䷎), #62 Lôi Sơn Tiểu Quá (䷽), #54 Lôi Trạch Quy Muội (䷵). On the San Yuan 360-degree Upper-Trigram Gua Qi compass ring, the 8 hexagrams sharing Upper Trigram Dui ☱ (all carrying Gua Qi 4 — Yin Metal (He Tu 4–9 Allied Metal)) are #58 Đoài Vi Trạch (䷹), #47 Trạch Thủy Khốn (䷮), #45 Trạch Địa Tụy (䷬), #31 Trạch Sơn Hàm (䷞), #43 Trạch Thiên Quải (䷪), #49 Trạch Hỏa Cách (䷰), #17 Trạch Lôi Tùy (䷐), #28 Trạch Phong Đại Quá (䷛).

Still water in a mountain valley reflects the stars. In the sacred architecture of Xuan Kong Da Gua (玄空大卦), the Dui Palace Group (兌宮八卦 — Nhóm Quái Đoài ☱) embodies the Youngest Daughter (Thiếu Nữ), joyous rhetoric, precious refined Yin Metal, and liquid financial circulation: holding Early Heaven Number 2 in the Southeast, Later Heaven Number 7 in Due West, and Gua Qi Number 4 (He Tu 4–9 Metal) on the outer trigram compass ring. In Period 9 (2024–2043), Dui holds the keys to both rapid magnetizing attraction via its 3rd-generation Parent Hexagram #31 Lake Mountain Xian (澤山咸 ䷞, Star Period 9) and unassailable wealth aggregation via #45 Lake Earth Cui (澤地萃 ䷬, built-in 4+6=10 Sum-of-Ten).

Master Ung Khiem (Thầy Ưng Khiêm)

Classical Feng Shui & East Asian Metaphysics Master · UK MASTER ACADEMY

Published June 24, 2026 · Updated October 15, 2026
7,800-word Scholarly Monograph · 28 min read
🇻🇳 Bản tiếng Việt

Dui Group (Lake ☱ · Đoài Cung) in Xuan Kong Da Gua Feng Shui

Core Trigram Palace Dossier: Dui Group ☱ Lake

Palace Family:

Dui Group (Lake ☱ · Đoài Cung) (兌宮八卦 · Youngest Daughter (Thiếu Nữ 少女))

Cosmic Image:

☱ Joyous Lake / Marsh (Zé 澤) — Trigram Element: Refined Yin Metal (Âm Kim 陰金)

Early & Later Bagua:

Early Heaven #2 (Southeast (Early Heaven Left Shoulder)) · Later Heaven #7 (Due West (Canh – Dậu – Tân · 247.5°–292.5°))

Da Gua Outer Qi:

Gua Qi 4 — Yin Metal (He Tu 4–9 Allied Metal)

Jing Fang 8 Gua:

#58 Đoài Vi Trạch (䷹), #47 Trạch Thủy Khốn (䷮), #45 Trạch Địa Tụy (䷬), #31 Trạch Sơn Hàm (䷞), #39 Thủy Sơn Kiển (䷦), #15 Địa Sơn Khiêm (䷎), #62 Lôi Sơn Tiểu Quá (䷽), #54 Lôi Trạch Quy Muội (䷵)

Upper-Dui Ring:

#58 Đoài Vi Trạch (䷹), #47 Trạch Thủy Khốn (䷮), #45 Trạch Địa Tụy (䷬), #31 Trạch Sơn Hàm (䷞), #43 Trạch Thiên Quải (䷪), #49 Trạch Hỏa Cách (䷰), #17 Trạch Lôi Tùy (䷐), #28 Trạch Phong Đại Quá (䷛)

Period 9 Crown Pair:

Direct Spirit: #31 Trạch Sơn Hàm ䷞ (Period 9) · Indirect Spirit: #58 Đoài Vi Trạch ䷹ (Period 1)

✦ Classical Key: In Period 9 (2024–2043), the Dui Group boasts three extraordinary treasures: (1) #31 Lake Mountain Xian (䷞, Gua Qi 4, Star Period 9) is a Ruling Period-9 Parent Direct Spirit; (2) #58 Dui Wei Ze (䷹, Gua Qi 4, Star Period 1) forms 1+9=10 Indirect Spirit water power; and (3) #15 Earth Mountain Qian (䷎, 5th Gen of Dui, Gua Qi 1, Period 4) is the only hexagram in the I Ching with all 6 lines auspicious!

Executive Summary for Practitioners & AI Search (GEO Summary)

Dual Classification Mastery: In Xuan Kong Da Gua (玄空大卦), the Dui Group (Lake ☱ · Đoài Cung) is analyzed across two interlocking axes: (1) the Jing Fang 8-Palace Lineage (Bát Cung Kinh Phòng) comprising #58 Đoài Vi Trạch (䷹), #47 Trạch Thủy Khốn (䷮), #45 Trạch Địa Tụy (䷬), #31 Trạch Sơn Hàm (䷞), #39 Thủy Sơn Kiển (䷦), #15 Địa Sơn Khiêm (䷎), #62 Lôi Sơn Tiểu Quá (䷽), #54 Lôi Trạch Quy Muội (䷵), and (2) the San Yuan Upper-Trigram Compass Ring comprising all 8 hexagrams with Dui ☱ as their Upper (Outer) Trigram (#58 Đoài Vi Trạch (䷹), #47 Trạch Thủy Khốn (䷮), #45 Trạch Địa Tụy (䷬), #31 Trạch Sơn Hàm (䷞), #43 Trạch Thiên Quải (䷪), #49 Trạch Hỏa Cách (䷰), #17 Trạch Lôi Tùy (䷐), #28 Trạch Phong Đại Quá (䷛)), which universally carry Gua Qi 4 (Yin Metal (He Tu 4–9 Allied Metal)).
Why the First 4 Hexagrams Overlap Both Systems: In Jing Fang's 8-step line transformation, Steps 0, 1, 2, and 3 (#58 Đoài Vi Trạch, #47 Trạch Thủy Khốn, #45 Trạch Địa Tụy, and #31 Trạch Sơn Hàm) transform only the Lower (Inner) Trigram while keeping Dui ☱ intact on top. Thus they hold Gua Qi 4 on the Luo Pan and belong to both lists simultaneously.
Supreme Resonance Partners: Every Upper-Dui hexagram (Gua Qi 4) locks into Sum of Ten (He Shi 合十) with the Gen Group ☶ (Gua Qi 6 Water · 4 + 6 = 10) and locks into He Tu Generative Difference of Five (He Sheng Cheng 合生成) with the Qian Group ☰ (Gua Qi 9 Metal · 4 – 9 Allied Metal).
Period 9 (2024–2043) Mountain & Water Formula: Anchor the Sitting Mountain, CEO Office, or Master Bed on the 3rd-Generation Parent Hexagram #31 Trạch Sơn Hàm (澤山咸 ䷞) at Khôn (208.125°–213.750°) (carrying Timely Star Period 9 Direct Spirit), and open the Main Gate, Driveway, or Water Mouth on the Pure Root Hexagram #58 Đoài Vi Trạch (兌為澤 ䷹) at Tân – Tuất (283.125°–288.750°) (carrying Star Period 1 to complete 1 + 9 = 10 Indirect Spirit wealth intake).
Sub-Degree 384-Yao Precision: Each hexagram spans 360° ÷ 64 = 5.625°, subdivided into 6 individual lines (yao) of 0.9375° each. Always align structural centerlines onto the Red Jewel Lines (Hồng Tâm Cát Hào)—most notably Yao 2 and Yao 5—while maintaining at least 0.75° clearance from inter-hexagram Void Lines (Không Vong).

1. Cosmological Identity, Early/Later Heaven Numerology & Classical Canon of the Dui Group (Lake ☱ · Đoài Cung)

Why do two houses sitting side by side on the exact same street—built in the same year and facing the same general compass octant—experience radically opposite destinies? One household rises into ministerial rank and generational liquidity. Its neighbor suffers relentless litigation, insolvent cash flow, and chronic illness. Standard 15°-mountain compasses cannot explain this divergence. Only Xuan Kong Da Gua (玄空大卦)—which slices the 360° horizon into 64 Early Heaven Hexagrams (5.625° per hexagram) and 384 individual yao lines (0.9375° per line)—exposes the sub-degree truth.

At the heart of this 64-hexagram cosmos stands the Dui Group (Lake ☱ · Đoài Cung) (兌宮八卦). To master its eight constituent hexagrams on a San Yuan Luo Pan, a practitioner must first internalize the three distinct numerical identities that Trigram Dui (兌 ☱) carries across the Theoretical Foundations of Chinese metaphysics:

1. Fu Xi Early Heaven Bagua Identity (Tiên Thiên Bát Quái — Primordial Cosmic Form): In Fu Xi's Early Heaven sequence, Dui ☱ holds Early Heaven Number 2 and resides at Southeast (Early Heaven Left Shoulder), embodying Joyous Lake / Marsh (Zé 澤) and the archetypal family role of Youngest Daughter (Thiếu Nữ 少女).
2. King Wen Later Heaven Bagua Identity (Hậu Thiên Bát Quái — Mundane Spatial Sector): When the trigrams descend into terrestrial manifestation under King Wen's Later Heaven arrangement, Dui ☱ moves to Due West (Canh – Dậu – Tân · 247.5°–292.5°) and governs Later Heaven Luo Shu Number 7, radiating the trigram Five Phase of Refined Yin Metal (Âm Kim 陰金).
3. San Yuan Xuan Kong Da Gua Outer Qi Identity ( Tiên Hậu Thiên Hợp Lạc Quái Khí): When Fu Xi's Early Heaven Bagua is superimposed directly onto the Nine Palaces of the Luo Shu Magic Square (“Nine at the head, One at the foot; Three on the left, Seven on the right; Two and Four at the shoulders; Six and Eight at the feet”), the Early Heaven position of Dui ☱ lands on Luo Shu Number 4! Converted through the He Tu Creation Formula (1–6 Water, 2–7 Fire, 3–8 Wood, 4–9 Metal), every hexagram with Dui ☱ as its Upper (Outer) Trigram carries Gua Qi 4 — Yin Metal (He Tu 4–9 Allied Metal).

「澤山咸卦少女配，山澤通氣合十位；下元九運正神臨，催官催貴發如雷。」 Zé Shān Xián guà shào nǚ pèi, shān zé tōng qì hé shí wèi; xià yuán jiǔ yùn zhèng shén lín, cuī guān cuī guì fā rú léi.
In Lake Mountain Xian the Youngest Daughter mates with the Youngest Son; Mountain and Lake exchange Qi in Sum-of-Ten harmony; when the Lower Cycle Period 9 Direct Spirit arrives, it accelerates official rank and nobility like thunder.
— Classical San Yuan Xuan Kong Da Gua Verse («Yu Han Tong Mi · Jade Casket Mystery»)

Read that classical verse again. Grandmaster Yang Yun Song and Grandmaster Jiang Da Hong never spoke of vague 45° sectors when they promised scholarly nobility and enduring dynastic wealth. They spoke of locking the Incoming Dragon, Sitting Mountain, Facing Direction, and Water Mouth into the pure hexagram veins of the Dui Group (Lake ☱ · Đoài Cung) and its resonant partners! Let us also recall the foundational canon of the Book of Changes (I Ching 周易) regarding the virtue of this palace:

「兌，說也。剛中而柔外，說以利貞，是以順乎天而應乎人。」 Duì, yuè yě. Gāng zhōng ér róu wài, yuè yǐ lì zhēn, shì yǐ shùn hū tiān ér yìng hū rén.
Dui means joyousness and eloquent persuasion. Firm at the center and gentle on the outside, joy rooted in uprightness accords with Heaven above and responds to humanity below.
— «Book of Changes · Commentary on the Judgments of Dui» (周易·兌卦·彖傳)

Numbers govern form. Form channels Qi. When you step onto a site with your Luo Pan, understanding how Early Heaven 2, Later Heaven 7, and Da Gua Outer Qi 4 interlock within the Dui Group (Lake ☱ · Đoài Cung) separates authentic lineage mastery from textbook guesswork.

2. Dual Classification Mechanics: Jing Fang 8-Palace Lineage vs. San Yuan Upper-Trigram Gua Qi 4 Ring

Stop right here. This is the exact junction where 90% of self-taught students get confused when cross-referencing classical I Ching manuals with a San Yuan Xuan Kong Da Gua compass! Why do some texts list the 8 hexagrams of the Dui Group (Lake ☱ · Đoài Cung) as #58 Đoài Vi Trạch (䷹), #47 Trạch Thủy Khốn (䷮), #45 Trạch Địa Tụy (䷬), #31 Trạch Sơn Hàm (䷞), #39 Thủy Sơn Kiển (䷦), #15 Địa Sơn Khiêm (䷎), #62 Lôi Sơn Tiểu Quá (䷽), #54 Lôi Trạch Quy Muội (䷵), whereas the outer Gua Qi table of a San Yuan Luo Pan lists the 8 hexagrams of Gua Qi 4 (Dui ☱) as #58 Đoài Vi Trạch (䷹), #47 Trạch Thủy Khốn (䷮), #45 Trạch Địa Tụy (䷬), #31 Trạch Sơn Hàm (䷞), #43 Trạch Thiên Quải (䷪), #49 Trạch Hỏa Cách (䷰), #17 Trạch Lôi Tùy (䷐), #28 Trạch Phong Đại Quá (䷛)? Both lists are 100% authentic. They simply represent the two orthogonal axes of The System of 64 Hexagrams:

AXIS 1 · ANCESTRAL SOUL

Jing Fang's Eight-Palace Transformation (Bát Cung Kinh Phòng 京房八宮)

Formulated by Western Han dynasty master Jing Fang (京房, 77–37 BCE) in the Jing Shi Yi Zhuan. Starting from the doubled pure hexagram #58 Đoài Vi Trạch (䷹), lines transform sequentially from bottom to top: 1st Yao (1st Gen), 2nd Yao (2nd Gen), 3rd Yao (3rd Gen), 4th Yao (4th Gen), 5th Yao (5th Gen), back to 4th Yao (Wandering Soul / Du Hồn), and finally restoring the lower 3 lines to the root trigram (Returning Soul / Quy Hồn). The 6th (top) line never changes because it guards the ancestral宗廟 temple.

AXIS 2 · COMPASS GUA QI

San Yuan Upper-Trigram Gua Qi Ring (Ngoại Quái Quái Khí 卦氣環)

On the 360° San Yuan Luo Pan, spatial Gua Qi (1–9) is determined exclusively by the Upper (Outer) Trigram, while temporal Gua Yun / Star Period (1–9) is determined by comparing which lines differ between the Upper and Lower Trigrams. Therefore, all 8 hexagrams that share Dui ☱ as their Upper Trigram share Gua Qi 4 (Yin Metal (He Tu 4–9 Allied Metal)) and span all 8 Star Periods (1, 2, 3, 4, 6, 7, 8, 9).

Look at the mathematical bridge between Axis 1 and Axis 2. In Jing Fang's 8-step transformation of the Dui Group (Lake ☱ · Đoài Cung):

Steps 0, 1, 2, and 3 (Pure Root #58, 1st Gen #47, 2nd Gen #45, and 3rd Gen #31): Because only the Lower (Inner) Trigram lines change during the first three generations, their Upper (Outer) Trigram remains Dui ☱! Consequently, these first four hexagrams carry Gua Qi 4 and belong to both the Jing Fang Dui Palace and the Upper-Dui Compass Ring! Specifically, Step 0 (#58 Đoài Vi Trạch) is the Period 1 Upper-Cycle Parent, Step 1 (#47 Trạch Thủy Khốn) is the Period 2 Jiangdong Hexagram, Step 2 (#45 Trạch Địa Tụy) is the Period 6 North-South Opposite Hexagram, and Step 3 (#31 Trạch Sơn Hàm) is the Period 9 Lower-Cycle Parent!
Steps 4, 5, 6, and 7 (4th Gen #39, 5th Gen #15, Wandering Soul #62, and Returning Soul #54): Once the Jing Fang transformation climbs into the 4th and 5th lines, the Upper Trigram changes from Dui ☱ into four other trigrams! On the Luo Pan, these four hexagrams adopt the Gua Qi number of their new Upper Trigram—while carrying Star Periods 8 (4th Gen), 4 (5th Gen), 7 (Wandering Soul), and 3 (Returning Soul).
The 4 Cross-Palace Complements (#43, #49, #17, and #28): Conversely, four hexagrams born as the 4th Gen, 5th Gen, Wandering Soul, and Returning Soul of other Jing Fang palaces acquire Dui ☱ as their Upper Trigram—supplying Star Periods 4, 3, 8, and 7 inside the Gua Qi 4 compass family!

Figure 1: The 8 Jing Fang Palace Hexagrams (Bát Cung Kinh Phòng) of the Dui Group (Lake ☱ · Đoài Cung) showing line-transformation steps, Gua Qi numbers, Star Periods, and 24-Mountain arcs.

By mastering both sets—all 8 Jing Fang Palace hexagrams and their 4 Upper-Dui Compass Ring complements (12 hexagrams in total, with 4 shared at the core)—you command the entire theoretical and practical spectrum of the Dui Group (Lake ☱ · Đoài Cung).

3. Master Reference Matrix: Complete 8 Jing Fang Palace Hexagrams & 8 Upper-Dui Compass Hexagrams

Before examining each hexagram line by line, consult the two master reference tables below. Table 1 synthesizes the 8 Jing Fang Palace Hexagrams of the Dui Group (Lake ☱ · Đoài Cung), while Table 2 synthesizes the 8 San Yuan Upper-Dui Compass Ring Hexagrams that share Gua Qi 4 (Yin Metal (He Tu 4–9 Allied Metal)).

Table 1: The 8 Jing Fang Palace Hexagrams (Bát Cung Kinh Phòng) of the Dui Group (Lake ☱ · Đoài Cung)
King Wen # & Hexagram	Jing Fang Step	Upper / Lower	Da Gua Qi & Element	Gua Yun (Star Period)	360° Compass Arc & Red Yao	Period 9 (2024–2043) Role
#58 Đoài Vi Trạch Dui (The Joyous Lake) · 兌為澤 ䷹	0. Pure Root (Bát Thuần)	Dui ☱ / Dui ☱	Gua Qi 4 Yin Metal (4-9 Metal)	Period 1 Greedy Wolf (Tan Lang)	Tân – Tuất (283.125°–288.750°) Red: Yao 2 (284.063°–285.000°), Yao 5 (286.875°–287.813°)	★ Supreme Period 9 Indirect Spirit (Period 1 + Period 9 = 10; Gua Qi 4 Metal)
#47 Trạch Thủy Khốn Kun (Exhaustion / Oppression) · 澤水困 ䷮	1. 1st Gen (Nhất Thế)	Dui ☱ / Kan ☵	Gua Qi 4 Yin Metal (4-9 Metal)	Period 2 Giant Gate (Ju Men)	Khôn – Thân (213.750°–219.375°) Red: Yao 2 (214.688°–215.625°), Yao 5 (217.500°–218.438°)	Upper Cycle Indirect Spirit (Gua Qi 4 Metal · Period 2)
#45 Trạch Địa Tụy Cui (Gathering Together) · 澤地萃 ䷬	2. 2nd Gen (Nhị Thế)	Dui ☱ / Kun ☷	Gua Qi 4 Yin Metal (4-9 Metal)	Period 6 Military Arts (Wu Qu)	Khôn – Thân (219.375°–225.000°) Red: Yao 2 (220.313°–221.250°), Yao 4 (222.188°–223.125°), Yao 5 (223.125°–224.063°)	Lower Cycle Direct Spirit Group (Internal Sum of Ten: Gua Qi 4 + Period 6 = 10)
#31 Trạch Sơn Hàm Xian (Influence / Mutual Attraction) · 澤山咸 ䷞	3. 3rd Gen (Tam Thế)	Dui ☱ / Gen ☶	Gua Qi 4 Yin Metal (4-9 Metal)	Period 9 Right Assistant (You Bi)	Khôn (208.125°–213.750°) Red: Yao 2 (209.063°–210.000°), Yao 4 (210.938°–211.875°), Yao 5 (211.875°–212.813°)	★ TIMELY PERIOD 9 PARENT DIRECT SPIRIT (Period 9 + Gua Qi 4 Metal)
#39 Thủy Sơn Kiển Jian (Obstruction) · 水山蹇 ䷦	4. 4th Gen (Tứ Thế)	Kan ☵ / Gen ☶	Gua Qi 7 Yang Fire (2-7 Fire)	Period 8 Left Assistant (Zuo Fu)	Dần (56.250°–61.875°) Red: Yao 3 (58.125°–59.063°), Yao 5 (60.000°–60.938°)	Lower Cycle Direct Spirit Group (4th Gen of Dui · Gua Qi 7 Fire · Period 8)
#15 Địa Sơn Khiêm Qian (Modesty / Humility) · 地山謙 ䷎	5. 5th Gen (Ngũ Thế)	Kun ☷ / Gen ☶	Gua Qi 1 Yang Water (1-6 Water)	Period 4 Literary Arts (Wen Qu)	Hợi (326.250°–331.875°) Red: Yao 1 (326.250°–327.188°), Yao 2 (327.188°–328.125°), Yao 3 (328.125°–329.063°), Yao 4 (329.063°–330.000°), Yao 5 (330.000°–330.938°), Yao 6 (330.938°–331.875°)	★ All-Six-Yao Auspicious Hexagram · Gua Qi 1 Sum-of-Ten with Period 9 (1+9=10)
#62 Lôi Sơn Tiểu Quá Xiao Guo (Preponderance of the Small) · 雷山小過 ䷽	6. Wandering Soul (Du Hồn)	Zhen ☳ / Gen ☶	Gua Qi 8 Yin Wood (3-8 Wood)	Period 7 Broken Army (Po Jun)	Bính – Ngọ (168.750°–174.375°) Red: Yao 2 (169.688°–170.625°), Yao 5 (172.500°–173.438°)	Lower Cycle Direct Spirit Group (Wandering Soul of Dui · Gua Qi 8 Wood · Period 7)
#54 Lôi Trạch Quy Muội Gui Mei (The Marrying Maiden) · 雷澤歸妹 ䷵	7. Returning Soul (Quy Hồn)	Zhen ☳ / Dui ☱	Gua Qi 8 Yin Wood (3-8 Wood)	Period 3 Rank / Lu Cun	Tỵ (151.875°–157.500°) Red: Yao 2 (152.813°–153.750°), Yao 5 (155.625°–156.563°)	Upper Cycle Indirect Spirit (Returning Soul of Dui · Gua Qi 8 Wood · Period 3)

Table 2: The 8 San Yuan Compass Ring Hexagrams Sharing Upper Trigram Dui ☱ (All Carrying Gua Qi 4 — Yin Metal (He Tu 4–9 Allied Metal))
King Wen # & Hexagram	Upper / Lower	Outer Gua Qi	Star Period (Gua Yun)	Jing Fang Overlap	360° Fu Xi Compass Arc	Sum-of-Ten (He Shi) Targets
#58 Đoài Vi Trạch (兌為澤 ䷹)	Dui ☱ / Dui ☱	Gua Qi 4 (Yin Metal)	Period 1 (Greedy Wolf (Tan Lang))	Yes (Steps 0–3)	Tân – Tuất (283.125°–288.750°)	Gua Qi 6 (He Shi) · Period 9 (He Shi)
#47 Trạch Thủy Khốn (澤水困 ䷮)	Dui ☱ / Kan ☵	Gua Qi 4 (Yin Metal)	Period 2 (Giant Gate (Ju Men))	Yes (Steps 0–3)	Khôn – Thân (213.750°–219.375°)	Gua Qi 6 (He Shi) · Period 8 (He Shi)
#45 Trạch Địa Tụy (澤地萃 ䷬)	Dui ☱ / Kun ☷	Gua Qi 4 (Yin Metal)	Period 6 (Military Arts (Wu Qu))	Yes (Steps 0–3)	Khôn – Thân (219.375°–225.000°)	Gua Qi 6 (He Shi) · Period 4 (He Shi)
#31 Trạch Sơn Hàm (澤山咸 ䷞)	Dui ☱ / Gen ☶	Gua Qi 4 (Yin Metal)	Period 9 (Right Assistant (You Bi))	Yes (Steps 0–3)	Khôn (208.125°–213.750°)	Gua Qi 6 (He Shi) · Period 1 (He Shi)
#43 Trạch Thiên Quải (澤天夬 ䷪)	Dui ☱ / Qian ☰	Gua Qi 4 (Yin Metal)	Period 4 (Literary Arts (Wen Qu))	Cross-Palace (Steps 4–7)	Tuất (294.375°–300.000°)	Gua Qi 6 (He Shi) · Period 6 (He Shi)
#49 Trạch Hỏa Cách (澤火革 ䷰)	Dui ☱ / Li ☲	Gua Qi 4 (Yin Metal)	Period 8 (Left Assistant (Zuo Fu))	Cross-Palace (Steps 4–7)	Tân – Tuất (288.750°–294.375°)	Gua Qi 6 (He Shi) · Period 2 (He Shi)
#17 Trạch Lôi Tùy (澤雷隨 ䷐)	Dui ☱ / Zhen ☳	Gua Qi 4 (Yin Metal)	Period 3 (Rank / Lu Cun)	Cross-Palace (Steps 4–7)	Dậu – Tân (277.500°–283.125°)	Gua Qi 6 (He Shi) · Period 7 (He Shi)
#28 Trạch Phong Đại Quá (澤風大過 ䷛)	Dui ☱ / Xun ☴	Gua Qi 4 (Yin Metal)	Period 7 (Broken Army (Po Jun))	Cross-Palace (Steps 4–7)	Mùi – Khôn (202.500°–208.125°)	Gua Qi 6 (He Shi) · Period 3 (He Shi)

Figure 2: Comparison of the 8 Upper-Dui Compass Ring Hexagrams (all carrying Gua Qi 4) and their overlap with the Jing Fang Dui Palace.

Notice the mathematical elegance in Table 2: within the 8 hexagrams sharing Upper Trigram Dui ☱, every single Star Period from 1 to 9 (excluding the central 5) appears exactly once (1, 2, 3, 4, 6, 7, 8, 9). Four belong to the Upper Cycle (Periods 1–2–3–4) and four belong to the Lower Cycle (Periods 6–7–8–9).

4. Deep-Dive Monograph Pt. I: Pure Root (Bát Thuần), 1st Generation, 2nd Generation & 3rd Generation Hexagrams

Let us now dissect the first four hexagrams of the Dui Group (Lake ☱ · Đoài Cung): #58 Đoài Vi Trạch (䷹), #47 Trạch Thủy Khốn (䷮), #45 Trạch Địa Tụy (䷬), and #31 Trạch Sơn Hàm (䷞). Because all four retain Dui ☱ as their Upper (Outer) Trigram, all four carry Gua Qi 4 (Yin Metal (He Tu 4–9 Allied Metal)) and progress from Pure Root (Period 1) through 1st Gen (Period 2) and 2nd Gen (Period 6) to culmination at the 3rd-Generation Parent Hexagram (Period 9)!

King Wen #58 · Duì Wéi Zé · Jing Fang Step 0

#58. Đoài Vi Trạch — Dui (The Joyous Lake) (兌為澤 ䷹) · Gua Qi 4 & Period 1

1. Structural & Trigram Anatomy: Upper (Outer) Trigram Dui ☱ over Lower (Inner) Trigram Dui ☱. Jing Fang Step 0: Pure Palace Root (Bát Thuần Quái · 八純卦). Because its Upper (Outer) Trigram is Dui ☱ and its Jing Fang transformation remains within the lower three lines, #58 Đoài Vi Trạch (兌為澤 ䷹) belongs simultaneously to the Jing Fang Dui Palace and the San Yuan Upper-Dui Gua Qi 4 Compass Ring. Measure the angle twice. Never guess.

2. Two-Ring Numerical Code (Gua Qi & Gua Yun): On the outer San Yuan Gua Qi ring, #58 Đoài Vi Trạch carries Gua Qi 4 (Yin Metal (4-9 Metal)), which achieves Sum-of-Ten (He Shi 合十) resonance with Gua Qi 6 (4 + 6 = 10) and He Tu Generative Difference-of-Five (He Sheng Cheng 合生成) with Gua Qi 9 (|4 − 9| = 5). On the inner Star Period ring, it carries Period 1 · Greedy Wolf (Tan Lang) (Upper Cycle Parent (Periods 1–4)), forming temporal Sum-of-Ten with Star Period 9 (1 + 9 = 10).

3. 360° Fu Xi Compass Arc & 384-Yao Line Division: Occupies the 5.625° horizon sector at Tân – Tuất (283.125°–288.750°) within the Tân (WNW) mountain sector. Its prime Auspicious Red Jewel Lines (Hồng Tâm Cát Hào) are Yao 2 (284.063°–285.000°), Yao 5 (286.875°–287.813°) (each spanning exactly 0.9375°). Practitioners must strictly avoid the Void Taboo Zones (Không Vong Tuyến) at 283.125° ±0.45°, 288.750° ±0.45°, where qi scatters into erratic turbulence.

4. Period 9 (2024–2043) Field Application (Sitting, Facing, Gate, Stove & Water): ★ Supreme Period 9 Indirect Spirit (Period 1 + Period 9 = 10; Gua Qi 4 Metal). One of the 8 Pure Period-1 Hexagrams forming Sum-of-Ten (1+9=10) with Period 9! Outstanding for Water Mouth, Main Entrance, financial reception, and public speaking. When activating #58 Đoài Vi Trạch via Xuan Kong Da Gua Date Selection, select Year, Month, Day, and Hour pillars carrying Gua Qi 4 (Pure One Qi), Gua Qi 6 (Sum of Ten), or Gua Qi 9 (He Tu Same-Element Completion).

King Wen #47 · Zé Shuǐ Kùn · Jing Fang Step 1

#47. Trạch Thủy Khốn — Kun (Exhaustion / Oppression) (澤水困 ䷮) · Gua Qi 4 & Period 2

1. Structural & Trigram Anatomy: Upper (Outer) Trigram Dui ☱ over Lower (Inner) Trigram Kan ☵. Jing Fang Step 1: 1st Generation (Nhất Thế Quái · 一世卦). Because its Upper (Outer) Trigram is Dui ☱ and its Jing Fang transformation remains within the lower three lines, #47 Trạch Thủy Khốn (澤水困 ䷮) belongs simultaneously to the Jing Fang Dui Palace and the San Yuan Upper-Dui Gua Qi 4 Compass Ring. Measure the angle twice. Never guess.

2. Two-Ring Numerical Code (Gua Qi & Gua Yun): On the outer San Yuan Gua Qi ring, #47 Trạch Thủy Khốn carries Gua Qi 4 (Yin Metal (4-9 Metal)), which achieves Sum-of-Ten (He Shi 合十) resonance with Gua Qi 6 (4 + 6 = 10) and He Tu Generative Difference-of-Five (He Sheng Cheng 合生成) with Gua Qi 9 (|4 − 9| = 5). On the inner Star Period ring, it carries Period 2 · Giant Gate (Ju Men) (Upper Cycle Jiangdong (1st Yao Change)), forming temporal Sum-of-Ten with Star Period 8 (2 + 8 = 10).

3. 360° Fu Xi Compass Arc & 384-Yao Line Division: Occupies the 5.625° horizon sector at Khôn – Thân (213.750°–219.375°) within the Khôn (SW) mountain sector. Its prime Auspicious Red Jewel Lines (Hồng Tâm Cát Hào) are Yao 2 (214.688°–215.625°), Yao 5 (217.500°–218.438°) (each spanning exactly 0.9375°). Practitioners must strictly avoid the Void Taboo Zones (Không Vong Tuyến) at 213.750° ±0.45°, 219.375° ±0.45°, where qi scatters into erratic turbulence.

4. Period 9 (2024–2043) Field Application (Sitting, Facing, Gate, Stove & Water): Upper Cycle Indirect Spirit (Gua Qi 4 Metal · Period 2). When left unbridged, Kun (#47) drains liquidity; when paired with Period 8 Da Guo (#28) via 2+8=10 and Gen Gua Qi 6 via 4+6=10 on Yao 2 or Yao 5, it transforms pressure into breakthrough. When activating #47 Trạch Thủy Khốn via Xuan Kong Da Gua Date Selection, select Year, Month, Day, and Hour pillars carrying Gua Qi 4 (Pure One Qi), Gua Qi 6 (Sum of Ten), or Gua Qi 9 (He Tu Same-Element Completion).

King Wen #45 · Zé Dì Cuì · Jing Fang Step 2

#45. Trạch Địa Tụy — Cui (Gathering Together) (澤地萃 ䷬) · Gua Qi 4 & Period 6

1. Structural & Trigram Anatomy: Upper (Outer) Trigram Dui ☱ over Lower (Inner) Trigram Kun ☷. Jing Fang Step 2: 2nd Generation (Nhị Thế Quái · 二世卦). Because its Upper (Outer) Trigram is Dui ☱ and its Jing Fang transformation remains within the lower three lines, #45 Trạch Địa Tụy (澤地萃 ䷬) belongs simultaneously to the Jing Fang Dui Palace and the San Yuan Upper-Dui Gua Qi 4 Compass Ring. Measure the angle twice. Never guess.

2. Two-Ring Numerical Code (Gua Qi & Gua Yun): On the outer San Yuan Gua Qi ring, #45 Trạch Địa Tụy carries Gua Qi 4 (Yin Metal (4-9 Metal)), which achieves Sum-of-Ten (He Shi 合十) resonance with Gua Qi 6 (4 + 6 = 10) and He Tu Generative Difference-of-Five (He Sheng Cheng 合生成) with Gua Qi 9 (|4 − 9| = 5). On the inner Star Period ring, it carries Period 6 · Military Arts (Wu Qu) (Lower Cycle North-South Opposite (2nd Gen of Dui)), forming temporal Sum-of-Ten with Star Period 4 (6 + 4 = 10).

3. 360° Fu Xi Compass Arc & 384-Yao Line Division: Occupies the 5.625° horizon sector at Khôn – Thân (219.375°–225.000°) within the Khôn / Thân (SW) mountain sector. Its prime Auspicious Red Jewel Lines (Hồng Tâm Cát Hào) are Yao 2 (220.313°–221.250°), Yao 4 (222.188°–223.125°), Yao 5 (223.125°–224.063°) (each spanning exactly 0.9375°). Practitioners must strictly avoid the Void Taboo Zones (Không Vong Tuyến) at 219.375° ±0.45°, 225.000° ±0.75° (Khôn–Thân 45° Corner Void), where qi scatters into erratic turbulence.

4. Period 9 (2024–2043) Field Application (Sitting, Facing, Gate, Stove & Water): Lower Cycle Direct Spirit Group (Internal Sum of Ten: Gua Qi 4 + Period 6 = 10). Treasure hexagram of talent and capital aggregation! Carries built-in Sum-of-Ten (Gua Qi 4 + Period 6 = 10). Superb for commercial Sitting Mountain or treasury vault. When activating #45 Trạch Địa Tụy via Xuan Kong Da Gua Date Selection, select Year, Month, Day, and Hour pillars carrying Gua Qi 4 (Pure One Qi), Gua Qi 6 (Sum of Ten), or Gua Qi 9 (He Tu Same-Element Completion).

King Wen #31 · Zé Shān Xián · Jing Fang Step 3

#31. Trạch Sơn Hàm — Xian (Influence / Mutual Attraction) (澤山咸 ䷞) · Gua Qi 4 & Period 9

1. Structural & Trigram Anatomy: Upper (Outer) Trigram Dui ☱ over Lower (Inner) Trigram Gen ☶. Jing Fang Step 3: 3rd Generation (Tam Thế Quái · 三世卦). Because its Upper (Outer) Trigram is Dui ☱ and its Jing Fang transformation remains within the lower three lines, #31 Trạch Sơn Hàm (澤山咸 ䷞) belongs simultaneously to the Jing Fang Dui Palace and the San Yuan Upper-Dui Gua Qi 4 Compass Ring. Measure the angle twice. Never guess.

2. Two-Ring Numerical Code (Gua Qi & Gua Yun): On the outer San Yuan Gua Qi ring, #31 Trạch Sơn Hàm carries Gua Qi 4 (Yin Metal (4-9 Metal)), which achieves Sum-of-Ten (He Shi 合十) resonance with Gua Qi 6 (4 + 6 = 10) and He Tu Generative Difference-of-Five (He Sheng Cheng 合生成) with Gua Qi 9 (|4 − 9| = 5). On the inner Star Period ring, it carries Period 9 · Right Assistant (You Bi) (Lower Cycle Parent (All 3 Yao Opposite · 3rd Gen of Dui)), forming temporal Sum-of-Ten with Star Period 1 (9 + 1 = 10).

3. 360° Fu Xi Compass Arc & 384-Yao Line Division: Occupies the 5.625° horizon sector at Khôn (208.125°–213.750°) within the Khôn (SW) mountain sector. Its prime Auspicious Red Jewel Lines (Hồng Tâm Cát Hào) are Yao 2 (209.063°–210.000°), Yao 4 (210.938°–211.875°), Yao 5 (211.875°–212.813°) (each spanning exactly 0.9375°). Practitioners must strictly avoid the Void Taboo Zones (Không Vong Tuyến) at 208.125° ±0.45°, 213.750° ±0.45°, where qi scatters into erratic turbulence.

4. Period 9 (2024–2043) Field Application (Sitting, Facing, Gate, Stove & Water): ★ TIMELY PERIOD 9 PARENT DIRECT SPIRIT (Period 9 + Gua Qi 4 Metal). Youngest Son (Gen) and Youngest Daughter (Dui) in total Yin-Yang resonance. One of the 8 Ruling Period-9 Parent Hexagrams! Unmatched for Sitting Mountain, Master Bedroom, and client magnetism. When activating #31 Trạch Sơn Hàm via Xuan Kong Da Gua Date Selection, select Year, Month, Day, and Hour pillars carrying Gua Qi 4 (Pure One Qi), Gua Qi 6 (Sum of Ten), or Gua Qi 9 (He Tu Same-Element Completion).

5. Deep-Dive Monograph Pt. II: 4th Generation, 5th Generation, Wandering Soul (Du Hồn) & Returning Soul (Quy Hồn)

Once the 3rd Generation (#31 Trạch Sơn Hàm) completes the transformation of the Lower Trigram, Jing Fang's line progression ascends into the Upper (Outer) Trigram across the 4th Generation (#39 Thủy Sơn Kiển), 5th Generation (#15 Địa Sơn Khiêm), Wandering Soul (#62 Lôi Sơn Tiểu Quá), and Returning Soul (#54 Lôi Trạch Quy Muội). Watch how the Outer Trigram shifts across the palaces while the inner ancestral pulse of the Dui Group (Lake ☱ · Đoài Cung) drives their destiny:

King Wen #39 · Shuǐ Shān Jiǎn · Jing Fang Step 4

#39. Thủy Sơn Kiển — Jian (Obstruction) (水山蹇 ䷦) · Gua Qi 7 & Period 8

1. Structural & Trigram Anatomy: Upper (Outer) Trigram Kan ☵ over Lower (Inner) Trigram Gen ☶. Jing Fang Step 4: 4th Generation (Tứ Thế Quái · 四世卦). In the Jing Fang 8-Palace sequence, the transformation has ascended into the Upper Trigram (shifting the Outer Trigram to Kan ☵), so on the San Yuan Luo Pan its spatial Gua Qi becomes Gua Qi 7 (Yang Fire (2-7 Fire)) while its ancestral soul remains rooted in the Dui Palace. Measure the angle twice. Never guess.

2. Two-Ring Numerical Code (Gua Qi & Gua Yun): On the outer San Yuan Gua Qi ring, #39 Thủy Sơn Kiển carries Gua Qi 7 (Yang Fire (2-7 Fire)), which achieves Sum-of-Ten (He Shi 合十) resonance with Gua Qi 3 (7 + 3 = 10) and He Tu Generative Difference-of-Five (He Sheng Cheng 合生成) with Gua Qi 2 (|7 − 2| = 5). On the inner Star Period ring, it carries Period 8 · Left Assistant (Zuo Fu) (Lower Cycle Jiangdong Opposite (4th Gen of Dui)), forming temporal Sum-of-Ten with Star Period 2 (8 + 2 = 10).

3. 360° Fu Xi Compass Arc & 384-Yao Line Division: Occupies the 5.625° horizon sector at Dần (56.250°–61.875°) within the Dần (ENE) mountain sector. Its prime Auspicious Red Jewel Lines (Hồng Tâm Cát Hào) are Yao 3 (58.125°–59.063°), Yao 5 (60.000°–60.938°) (each spanning exactly 0.9375°). Practitioners must strictly avoid the Void Taboo Zones (Không Vong Tuyến) at 56.250° ±0.45°, 61.875° ±0.45°, where qi scatters into erratic turbulence.

4. Period 9 (2024–2043) Field Application (Sitting, Facing, Gate, Stove & Water): Lower Cycle Direct Spirit Group (4th Gen of Dui · Gua Qi 7 Fire · Period 8). On Yao 5 ('Great Jian, friends come'), this northeast Dần sector anchors resilient mountain backing and pairs with Li Gua Qi 3 (7+3=10). When activating #39 Thủy Sơn Kiển via Xuan Kong Da Gua Date Selection, select Year, Month, Day, and Hour pillars carrying Gua Qi 7 (Pure One Qi), Gua Qi 3 (Sum of Ten), or Gua Qi 2 (He Tu Same-Element Completion).

King Wen #15 · Dì Shān Qiān · Jing Fang Step 5

#15. Địa Sơn Khiêm — Qian (Modesty / Humility) (地山謙 ䷎) · Gua Qi 1 & Period 4

1. Structural & Trigram Anatomy: Upper (Outer) Trigram Kun ☷ over Lower (Inner) Trigram Gen ☶. Jing Fang Step 5: 5th Generation (Ngũ Thế Quái · 五世卦). In the Jing Fang 8-Palace sequence, the transformation has ascended into the Upper Trigram (shifting the Outer Trigram to Kun ☷), so on the San Yuan Luo Pan its spatial Gua Qi becomes Gua Qi 1 (Yang Water (1-6 Water)) while its ancestral soul remains rooted in the Dui Palace. Measure the angle twice. Never guess.

2. Two-Ring Numerical Code (Gua Qi & Gua Yun): On the outer San Yuan Gua Qi ring, #15 Địa Sơn Khiêm carries Gua Qi 1 (Yang Water (1-6 Water)), which achieves Sum-of-Ten (He Shi 合十) resonance with Gua Qi 9 (1 + 9 = 10) and He Tu Generative Difference-of-Five (He Sheng Cheng 合生成) with Gua Qi 6 (|1 − 6| = 5). On the inner Star Period ring, it carries Period 4 · Literary Arts (Wen Qu) (Upper Cycle North-South (5th Gen of Dui)), forming temporal Sum-of-Ten with Star Period 6 (4 + 6 = 10).

3. 360° Fu Xi Compass Arc & 384-Yao Line Division: Occupies the 5.625° horizon sector at Hợi (326.250°–331.875°) within the Hợi (NNW) mountain sector. Its prime Auspicious Red Jewel Lines (Hồng Tâm Cát Hào) are Yao 1 (326.250°–327.188°), Yao 2 (327.188°–328.125°), Yao 3 (328.125°–329.063°), Yao 4 (329.063°–330.000°), Yao 5 (330.000°–330.938°), Yao 6 (330.938°–331.875°) (each spanning exactly 0.9375°). Practitioners must strictly avoid the Void Taboo Zones (Không Vong Tuyến) at 326.250° ±0.45°, 331.875° ±0.45°, where qi scatters into erratic turbulence.

4. Period 9 (2024–2043) Field Application (Sitting, Facing, Gate, Stove & Water): ★ All-Six-Yao Auspicious Hexagram · Gua Qi 1 Sum-of-Ten with Period 9 (1+9=10). The only hexagram in the I Ching where all 6 lines are auspicious! Carries Gua Qi 1 (forming 1+9=10 with Qian 9) and Period 4 (forming 4+6=10 with Period 6). Exceptional for Water Mouth and Main Gate. When activating #15 Địa Sơn Khiêm via Xuan Kong Da Gua Date Selection, select Year, Month, Day, and Hour pillars carrying Gua Qi 1 (Pure One Qi), Gua Qi 9 (Sum of Ten), or Gua Qi 6 (He Tu Same-Element Completion).

King Wen #62 · Léi Shān Xiǎo Guò · Jing Fang Step 6

#62. Lôi Sơn Tiểu Quá — Xiao Guo (Preponderance of the Small) (雷山小過 ䷽) · Gua Qi 8 & Period 7

1. Structural & Trigram Anatomy: Upper (Outer) Trigram Zhen ☳ over Lower (Inner) Trigram Gen ☶. Jing Fang Step 6: Wandering Soul (Du Hồn Quái · 遊魂卦). In the Jing Fang 8-Palace sequence, the transformation has ascended into the Upper Trigram (shifting the Outer Trigram to Zhen ☳), so on the San Yuan Luo Pan its spatial Gua Qi becomes Gua Qi 8 (Yin Wood (3-8 Wood)) while its ancestral soul remains rooted in the Dui Palace. Measure the angle twice. Never guess.

2. Two-Ring Numerical Code (Gua Qi & Gua Yun): On the outer San Yuan Gua Qi ring, #62 Lôi Sơn Tiểu Quá carries Gua Qi 8 (Yin Wood (3-8 Wood)), which achieves Sum-of-Ten (He Shi 合十) resonance with Gua Qi 2 (8 + 2 = 10) and He Tu Generative Difference-of-Five (He Sheng Cheng 合生成) with Gua Qi 3 (|8 − 3| = 5). On the inner Star Period ring, it carries Period 7 · Broken Army (Po Jun) (Lower Cycle Jiangxi Opposite (Wandering Soul of Dui)), forming temporal Sum-of-Ten with Star Period 3 (7 + 3 = 10).

3. 360° Fu Xi Compass Arc & 384-Yao Line Division: Occupies the 5.625° horizon sector at Bính – Ngọ (168.750°–174.375°) within the Bính / Ngọ (SSE) mountain sector. Its prime Auspicious Red Jewel Lines (Hồng Tâm Cát Hào) are Yao 2 (169.688°–170.625°), Yao 5 (172.500°–173.438°) (each spanning exactly 0.9375°). Practitioners must strictly avoid the Void Taboo Zones (Không Vong Tuyến) at 168.750° ±0.45°, 174.375° ±0.45°, where qi scatters into erratic turbulence.

4. Period 9 (2024–2043) Field Application (Sitting, Facing, Gate, Stove & Water): Lower Cycle Direct Spirit Group (Wandering Soul of Dui · Gua Qi 8 Wood · Period 7). Favors conservative precision and financial auditing when tapped on Yao 2; pairs with Xun Gua Qi 2 (8+2=10) and Period 3 (7+3=10). When activating #62 Lôi Sơn Tiểu Quá via Xuan Kong Da Gua Date Selection, select Year, Month, Day, and Hour pillars carrying Gua Qi 8 (Pure One Qi), Gua Qi 2 (Sum of Ten), or Gua Qi 3 (He Tu Same-Element Completion).

King Wen #54 · Léi Zé Guī Mèi · Jing Fang Step 7

#54. Lôi Trạch Quy Muội — Gui Mei (The Marrying Maiden) (雷澤歸妹 ䷵) · Gua Qi 8 & Period 3

1. Structural & Trigram Anatomy: Upper (Outer) Trigram Zhen ☳ over Lower (Inner) Trigram Dui ☱. Jing Fang Step 7: Returning Soul (Quy Hồn Quái · 歸魂卦). In the Jing Fang 8-Palace sequence, the transformation has ascended into the Upper Trigram (shifting the Outer Trigram to Zhen ☳), so on the San Yuan Luo Pan its spatial Gua Qi becomes Gua Qi 8 (Yin Wood (3-8 Wood)) while its ancestral soul remains rooted in the Dui Palace. Measure the angle twice. Never guess.

2. Two-Ring Numerical Code (Gua Qi & Gua Yun): On the outer San Yuan Gua Qi ring, #54 Lôi Trạch Quy Muội carries Gua Qi 8 (Yin Wood (3-8 Wood)), which achieves Sum-of-Ten (He Shi 合十) resonance with Gua Qi 2 (8 + 2 = 10) and He Tu Generative Difference-of-Five (He Sheng Cheng 合生成) with Gua Qi 3 (|8 − 3| = 5). On the inner Star Period ring, it carries Period 3 · Rank / Lu Cun (Upper Cycle Jiangxi (Returning Soul of Dui)), forming temporal Sum-of-Ten with Star Period 7 (3 + 7 = 10).

3. 360° Fu Xi Compass Arc & 384-Yao Line Division: Occupies the 5.625° horizon sector at Tỵ (151.875°–157.500°) within the Tỵ (SSE) mountain sector. Its prime Auspicious Red Jewel Lines (Hồng Tâm Cát Hào) are Yao 2 (152.813°–153.750°), Yao 5 (155.625°–156.563°) (each spanning exactly 0.9375°). Practitioners must strictly avoid the Void Taboo Zones (Không Vong Tuyến) at 151.875° ±0.45°, 157.500° ±0.75° (Tỵ–Bính Palace Border), where qi scatters into erratic turbulence.

4. Period 9 (2024–2043) Field Application (Sitting, Facing, Gate, Stove & Water): Upper Cycle Indirect Spirit (Returning Soul of Dui · Gua Qi 8 Wood · Period 3). Returning Soul of Dui Palace. Must only be used on Yao 5 ('Emperor Yi gives his daughter in marriage') for secondary water features paired with Xun Gua Qi 2 (8+2=10). When activating #54 Lôi Trạch Quy Muội via Xuan Kong Da Gua Date Selection, select Year, Month, Day, and Hour pillars carrying Gua Qi 8 (Pure One Qi), Gua Qi 2 (Sum of Ten), or Gua Qi 3 (He Tu Same-Element Completion).

6. Upper-Dui Compass Ring Equivalents: The 4 Cross-Palace Hexagrams Completing the Gua Qi 4 Family

When you stand at the center of a building holding a San Yuan Xuan Kong Da Gua Luo Pan and look for sectors carrying Gua Qi 4 (Yin Metal (He Tu 4–9 Allied Metal))—whether to build a Pure One Hexagram (Yi Gua Chun Qing) formation or to lock into Sum-of-Ten with Gen Group ☶ (Gua Qi 6 Water · 4 + 6 = 10)—you must also command the four hexagrams whose Upper Trigram is Dui ☱ even though their Jing Fang root lies in another palace: #43 Trạch Thiên Quải (䷪), #49 Trạch Hỏa Cách (䷰), #17 Trạch Lôi Tùy (䷐), and #28 Trạch Phong Đại Quá (䷛).

King Wen #43 · Zé Tiān Guài · Upper-Dui Compass Ring Member · North-South Eight Spirits (Literary · Wen Qu) — Only 3rd (top) Yao differs from Upper Trigram

#43. Trạch Thiên Quải — Guai (Breakthrough / Resoluteness) (澤天夬 ䷪) · Gua Qi 4 & Period 4

1. Structural & Trigram Anatomy: Upper (Outer) Trigram Dui ☱ over Lower (Inner) Trigram Qian ☰. Upper-Dui Compass Ring Member · North-South Eight Spirits (Literary · Wen Qu) — Only 3rd (top) Yao differs from Upper Trigram. While its Jing Fang ancestral root belongs to another palace's 4th/5th/Soul step, its Outer (Upper) Trigram is Dui ☱—meaning on the 360° San Yuan Luo Pan it carries pure Gua Qi 4 (Yin Metal (He Tu 4–9 Allied Metal)) and completes the 8-hexagram Upper-Dui ring! Measure the angle twice. Never guess.

2. Two-Ring Numerical Code (Gua Qi & Gua Yun): On the outer San Yuan Gua Qi ring, #43 Trạch Thiên Quải carries Gua Qi 4 (Yin Metal (4-9 Metal)), which achieves Sum-of-Ten (He Shi 合十) resonance with Gua Qi 6 (4 + 6 = 10) and He Tu Generative Difference-of-Five (He Sheng Cheng 合生成) with Gua Qi 9 (|4 − 9| = 5). On the inner Star Period ring, it carries Period 4 · Literary Arts (Wen Qu) (Upper Cycle North-South (3rd Yao Change · 5th Gen of Kun)), forming temporal Sum-of-Ten with Star Period 6 (4 + 6 = 10).

3. 360° Fu Xi Compass Arc & 384-Yao Line Division: Occupies the 5.625° horizon sector at Tuất (294.375°–300.000°) within the Tuất (WNW) mountain sector. Its prime Auspicious Red Jewel Lines (Hồng Tâm Cát Hào) are Yao 2 (295.313°–296.250°), Yao 5 (298.125°–299.063°) (each spanning exactly 0.9375°). Practitioners must strictly avoid the Void Taboo Zones (Không Vong Tuyến) at 294.375° ±0.45°, 300.000° ±0.75° (Tuất–Càn Palace Boundary), where qi scatters into erratic turbulence.

4. Period 9 (2024–2043) Field Application (Sitting, Facing, Gate, Stove & Water): Upper-Dui Gua Qi 4 Metal · Double-4 Literary Indirect Spirit. Upper-Dui compass hexagram (Gua Qi 4 + Period 4) and 5th Generation of Kun Palace. Forms Double Sum-of-Ten (4+6=10 in both Gua Qi and Period) with Gen #26 Da Chu (Gua Qi 6, Period 6)! When activating #43 Trạch Thiên Quải via Xuan Kong Da Gua Date Selection, select Year, Month, Day, and Hour pillars carrying Gua Qi 4 (Pure One Qi), Gua Qi 6 (Sum of Ten), or Gua Qi 9 (He Tu Same-Element Completion).

King Wen #49 · Zé Huǒ Gé · Upper-Dui Compass Ring Member · Jiangdong Opposite (Left Assistant · Zuo Fu) — 2nd & 3rd Yao differ from Upper Trigram (1st changed from Period 9)

#49. Trạch Hỏa Cách — Ge (Revolution / Molting) (澤火革 ䷰) · Gua Qi 4 & Period 8

1. Structural & Trigram Anatomy: Upper (Outer) Trigram Dui ☱ over Lower (Inner) Trigram Li ☲. Upper-Dui Compass Ring Member · Jiangdong Opposite (Left Assistant · Zuo Fu) — 2nd & 3rd Yao differ from Upper Trigram (1st changed from Period 9). While its Jing Fang ancestral root belongs to another palace's 4th/5th/Soul step, its Outer (Upper) Trigram is Dui ☱—meaning on the 360° San Yuan Luo Pan it carries pure Gua Qi 4 (Yin Metal (He Tu 4–9 Allied Metal)) and completes the 8-hexagram Upper-Dui ring! Measure the angle twice. Never guess.

2. Two-Ring Numerical Code (Gua Qi & Gua Yun): On the outer San Yuan Gua Qi ring, #49 Trạch Hỏa Cách carries Gua Qi 4 (Yin Metal (4-9 Metal)), which achieves Sum-of-Ten (He Shi 合十) resonance with Gua Qi 6 (4 + 6 = 10) and He Tu Generative Difference-of-Five (He Sheng Cheng 合生成) with Gua Qi 9 (|4 − 9| = 5). On the inner Star Period ring, it carries Period 8 · Left Assistant (Zuo Fu) (Lower Cycle Jiangdong Opposite (4th Gen of Kan)), forming temporal Sum-of-Ten with Star Period 2 (8 + 2 = 10).

3. 360° Fu Xi Compass Arc & 384-Yao Line Division: Occupies the 5.625° horizon sector at Tân – Tuất (288.750°–294.375°) within the Tân / Tuất (WNW) mountain sector. Its prime Auspicious Red Jewel Lines (Hồng Tâm Cát Hào) are Yao 4 (291.563°–292.500°), Yao 5 (292.500°–293.438°) (each spanning exactly 0.9375°). Practitioners must strictly avoid the Void Taboo Zones (Không Vong Tuyến) at 288.750° ±0.45°, 294.375° ±0.45°, where qi scatters into erratic turbulence.

4. Period 9 (2024–2043) Field Application (Sitting, Facing, Gate, Stove & Water): Upper-Dui Gua Qi 4 Metal · Lower Cycle Period 8 Direct Spirit Group. On Yao 5 ('The大人 Adult Tiger changes its stripes'), Ge (#49) empowers corporate restructuring, technological innovation, and decisive leadership. When activating #49 Trạch Hỏa Cách via Xuan Kong Da Gua Date Selection, select Year, Month, Day, and Hour pillars carrying Gua Qi 4 (Pure One Qi), Gua Qi 6 (Sum of Ten), or Gua Qi 9 (He Tu Same-Element Completion).

King Wen #17 · Zé Léi Suí · Upper-Dui Compass Ring Member · Jiangxi Hexagram (Rank · Lu Cun) — Only 2nd (middle) Yao differs from Upper Trigram

#17. Trạch Lôi Tùy — Sui (Following) (澤雷隨 ䷐) · Gua Qi 4 & Period 3

1. Structural & Trigram Anatomy: Upper (Outer) Trigram Dui ☱ over Lower (Inner) Trigram Zhen ☳. Upper-Dui Compass Ring Member · Jiangxi Hexagram (Rank · Lu Cun) — Only 2nd (middle) Yao differs from Upper Trigram. While its Jing Fang ancestral root belongs to another palace's 4th/5th/Soul step, its Outer (Upper) Trigram is Dui ☱—meaning on the 360° San Yuan Luo Pan it carries pure Gua Qi 4 (Yin Metal (He Tu 4–9 Allied Metal)) and completes the 8-hexagram Upper-Dui ring! Measure the angle twice. Never guess.

2. Two-Ring Numerical Code (Gua Qi & Gua Yun): On the outer San Yuan Gua Qi ring, #17 Trạch Lôi Tùy carries Gua Qi 4 (Yin Metal (4-9 Metal)), which achieves Sum-of-Ten (He Shi 合十) resonance with Gua Qi 6 (4 + 6 = 10) and He Tu Generative Difference-of-Five (He Sheng Cheng 合生成) with Gua Qi 9 (|4 − 9| = 5). On the inner Star Period ring, it carries Period 3 · Rank / Lu Cun (Upper Cycle Jiangxi (Returning Soul of Zhen)), forming temporal Sum-of-Ten with Star Period 7 (3 + 7 = 10).

3. 360° Fu Xi Compass Arc & 384-Yao Line Division: Occupies the 5.625° horizon sector at Dậu – Tân (277.500°–283.125°) within the Dậu / Tân (W) mountain sector. Its prime Auspicious Red Jewel Lines (Hồng Tâm Cát Hào) are Yao 1 (277.500°–278.438°), Yao 4 (280.313°–281.250°), Yao 5 (281.250°–282.188°) (each spanning exactly 0.9375°). Practitioners must strictly avoid the Void Taboo Zones (Không Vong Tuyến) at 277.500° ±0.75° (Dậu–Tân Palace Border), 283.125° ±0.45°, where qi scatters into erratic turbulence.

4. Period 9 (2024–2043) Field Application (Sitting, Facing, Gate, Stove & Water): Upper-Dui Gua Qi 4 Metal · Returning Soul of Zhen (Period 3 Indirect Spirit). Eldest Son (Zhen) bows beneath Youngest Daughter (Dui). Excellent for commercial storefronts, hospitality gates, and customer flow when paired with Gen Gua Qi 6 (4+6=10). When activating #17 Trạch Lôi Tùy via Xuan Kong Da Gua Date Selection, select Year, Month, Day, and Hour pillars carrying Gua Qi 4 (Pure One Qi), Gua Qi 6 (Sum of Ten), or Gua Qi 9 (He Tu Same-Element Completion).

King Wen #28 · Zé Fēng Dà Guò · Upper-Dui Compass Ring Member · Jiangxi Opposite (Broken Army · Po Jun) — 1st & 3rd Yao differ from Upper Trigram (2nd changed from Period 9)

#28. Trạch Phong Đại Quá — Da Guo (Preponderance of the Great) (澤風大過 ䷛) · Gua Qi 4 & Period 7

1. Structural & Trigram Anatomy: Upper (Outer) Trigram Dui ☱ over Lower (Inner) Trigram Xun ☴. Upper-Dui Compass Ring Member · Jiangxi Opposite (Broken Army · Po Jun) — 1st & 3rd Yao differ from Upper Trigram (2nd changed from Period 9). While its Jing Fang ancestral root belongs to another palace's 4th/5th/Soul step, its Outer (Upper) Trigram is Dui ☱—meaning on the 360° San Yuan Luo Pan it carries pure Gua Qi 4 (Yin Metal (He Tu 4–9 Allied Metal)) and completes the 8-hexagram Upper-Dui ring! Measure the angle twice. Never guess.

2. Two-Ring Numerical Code (Gua Qi & Gua Yun): On the outer San Yuan Gua Qi ring, #28 Trạch Phong Đại Quá carries Gua Qi 4 (Yin Metal (4-9 Metal)), which achieves Sum-of-Ten (He Shi 合十) resonance with Gua Qi 6 (4 + 6 = 10) and He Tu Generative Difference-of-Five (He Sheng Cheng 合生成) with Gua Qi 9 (|4 − 9| = 5). On the inner Star Period ring, it carries Period 7 · Broken Army (Po Jun) (Lower Cycle Jiangxi Opposite (Wandering Soul of Zhen)), forming temporal Sum-of-Ten with Star Period 3 (7 + 3 = 10).

3. 360° Fu Xi Compass Arc & 384-Yao Line Division: Occupies the 5.625° horizon sector at Mùi – Khôn (202.500°–208.125°) within the Khôn (SW) mountain sector. Its prime Auspicious Red Jewel Lines (Hồng Tâm Cát Hào) are Yao 2 (203.438°–204.375°), Yao 4 (205.313°–206.250°) (each spanning exactly 0.9375°). Practitioners must strictly avoid the Void Taboo Zones (Không Vong Tuyến) at 202.500° ±0.75° (Mùi–Khôn Palace Border), 208.125° ±0.45°, where qi scatters into erratic turbulence.

4. Period 9 (2024–2043) Field Application (Sitting, Facing, Gate, Stove & Water): Upper-Dui Gua Qi 4 Metal · Wandering Soul of Zhen (Lower Cycle Period 7). Must be anchored strictly on Yao 2 ('withered poplar sprouts shoots') or Yao 4 ('ridgepole braced') to avoid structural overextension. When activating #28 Trạch Phong Đại Quá via Xuan Kong Da Gua Date Selection, select Year, Month, Day, and Hour pillars carrying Gua Qi 4 (Pure One Qi), Gua Qi 6 (Sum of Ten), or Gua Qi 9 (He Tu Same-Element Completion).

7. 360° Fu Xi Circular Ring & 384-Yao Line Division: Auspicious Red Jewel Lines vs. Void Taboos (Không Vong)

Precision is the lifeblood of The Compass in Practice. On Fu Xi's 360° Early Heaven Circular Ring (Tiên Thiên 64 Quái Viên Đồ), the left semicircle from Due North (0° Mid-Tý, starting at #24 Fu ䷗) clockwise to Due South (180° Mid-Ngọ, culminating at #1 Qian ䷀) comprises the 32 Yang-Born Hexagrams, where individual yao lines count clockwise from Yao 1 to Yao 6. Conversely, the right semicircle from Due South (180° Mid-Ngọ, starting at #44 Gou ䷫) clockwise to Due North (360° Mid-Tý, culminating at #2 Kun ䷁) comprises the 32 Yin-Born Hexagrams.

Every hexagram occupies exactly 360° ÷ 64 = 5.625°. Divided across its six lines (Yao 1 at the bottom through Yao 6 at the top), each individual line spans:

1 Hexagram Arc = 5.625° | 1 Individual Yao Arc = 5.625° ÷ 6 = 0.9375° (56 minutes 15 seconds of arc)

Why do veteran masters insist on sighting the Red Jewel Lines (Hồng Tâm Cát Hào / 珠寶線) while treating inter-hexagram boundaries as lethal taboo zones? Because at the exact degree where one hexagram ends and the next begins, electromagnetic and geomagnetic vectors cancel each other out:

1. Eight-Trigram Palace Boundary Great Void (Đại Không Vong Tuyến 大空亡): Occurs at the 8 cardinal and intercardinal boundaries separating the 8 Trigram Palaces (0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°) and the 24-Mountain seams within±0.75°. Setting a house spine or main gate here invites bankruptcy, severe neurological or cardiovascular illness, and fractured lineage.
2. Inter-Hexagram Small Void (Tiểu Không Vong Tuyến 小空亡): Occurs at the 64-hexagram seam every 5.625° (within ±0.45° of the border between Yao 6 of one hexagram and Yao 1 of the adjacent hexagram).
3. Intra-Hexagram Yin-Yang Line Transition (Âm Dương Sai Thác): Even inside a single hexagram, the micro-seam between a Yang line and an adjacent Yin line should be avoided; always lock your sighting thread onto the central core of Yao 2 (the Earth Official line) or Yao 5 (the Heaven Sovereign line)!

Figure 3: High-precision 384-Yao angular breakdown (`0.9375°` per line) of the Period-9 Crown Hexagram #31 Trạch Sơn Hàm (澤山咸 ䷞), highlighting Red Jewel Lines versus Void Taboo boundaries.

Table 3: Complete 384-Yao Compass Degree Breakdown, Red Jewel Lines & Void Taboos for All 12 Hexagrams Associated with the Dui Group (Lake ☱ · Đoài Cung)
Hexagram	5.625° Horizon Sector	Inner Trigram Yao (1–3)	Outer Trigram Yao (4–6)	Auspicious Red Jewel Yao	Void Taboo Seams (Avoid!)
#58 Đoài Vi Trạch ䷹ Gua Qi 4 · Period 1	Tân – Tuất (283.125°–288.750°) 24-Mtn: Tân (WNW)	Y1: 283.12°–284.06° Y2: 284.06°–285.00° Y3: 285.00°–285.94°	Y4: 285.94°–286.88° Y5: 286.88°–287.81° Y6: 287.81°–288.75°	Yao 2 (284.063°–285.000°), Yao 5 (286.875°–287.813°)	283.125° ±0.45°, 288.750° ±0.45°
#47 Trạch Thủy Khốn ䷮ Gua Qi 4 · Period 2	Khôn – Thân (213.750°–219.375°) 24-Mtn: Khôn (SW)	Y1: 213.75°–214.69° Y2: 214.69°–215.62° Y3: 215.62°–216.56°	Y4: 216.56°–217.50° Y5: 217.50°–218.44° Y6: 218.44°–219.38°	Yao 2 (214.688°–215.625°), Yao 5 (217.500°–218.438°)	213.750° ±0.45°, 219.375° ±0.45°
#45 Trạch Địa Tụy ䷬ Gua Qi 4 · Period 6	Khôn – Thân (219.375°–225.000°) 24-Mtn: Khôn / Thân (SW)	Y1: 219.38°–220.31° Y2: 220.31°–221.25° Y3: 221.25°–222.19°	Y4: 222.19°–223.12° Y5: 223.12°–224.06° Y6: 224.06°–225.00°	Yao 2 (220.313°–221.250°), Yao 4 (222.188°–223.125°), Yao 5 (223.125°–224.063°)	219.375° ±0.45°, 225.000° ±0.75° (Khôn–Thân 45° Corner Void)
#31 Trạch Sơn Hàm ䷞ Gua Qi 4 · Period 9	Khôn (208.125°–213.750°) 24-Mtn: Khôn (SW)	Y1: 208.12°–209.06° Y2: 209.06°–210.00° Y3: 210.00°–210.94°	Y4: 210.94°–211.88° Y5: 211.88°–212.81° Y6: 212.81°–213.75°	Yao 2 (209.063°–210.000°), Yao 4 (210.938°–211.875°), Yao 5 (211.875°–212.813°)	208.125° ±0.45°, 213.750° ±0.45°
#39 Thủy Sơn Kiển ䷦ Gua Qi 7 · Period 8	Dần (56.250°–61.875°) 24-Mtn: Dần (ENE)	Y1: 56.25°–57.19° Y2: 57.19°–58.12° Y3: 58.12°–59.06°	Y4: 59.06°–60.00° Y5: 60.00°–60.94° Y6: 60.94°–61.88°	Yao 3 (58.125°–59.063°), Yao 5 (60.000°–60.938°)	56.250° ±0.45°, 61.875° ±0.45°
#15 Địa Sơn Khiêm ䷎ Gua Qi 1 · Period 4	Hợi (326.250°–331.875°) 24-Mtn: Hợi (NNW)	Y1: 326.25°–327.19° Y2: 327.19°–328.12° Y3: 328.12°–329.06°	Y4: 329.06°–330.00° Y5: 330.00°–330.94° Y6: 330.94°–331.88°	Yao 1 (326.250°–327.188°), Yao 2 (327.188°–328.125°), Yao 3 (328.125°–329.063°), Yao 4 (329.063°–330.000°), Yao 5 (330.000°–330.938°), Yao 6 (330.938°–331.875°)	326.250° ±0.45°, 331.875° ±0.45°
#62 Lôi Sơn Tiểu Quá ䷽ Gua Qi 8 · Period 7	Bính – Ngọ (168.750°–174.375°) 24-Mtn: Bính / Ngọ (SSE)	Y1: 168.75°–169.69° Y2: 169.69°–170.62° Y3: 170.62°–171.56°	Y4: 171.56°–172.50° Y5: 172.50°–173.44° Y6: 173.44°–174.38°	Yao 2 (169.688°–170.625°), Yao 5 (172.500°–173.438°)	168.750° ±0.45°, 174.375° ±0.45°
#54 Lôi Trạch Quy Muội ䷵ Gua Qi 8 · Period 3	Tỵ (151.875°–157.500°) 24-Mtn: Tỵ (SSE)	Y1: 151.88°–152.81° Y2: 152.81°–153.75° Y3: 153.75°–154.69°	Y4: 154.69°–155.62° Y5: 155.62°–156.56° Y6: 156.56°–157.50°	Yao 2 (152.813°–153.750°), Yao 5 (155.625°–156.563°)	151.875° ±0.45°, 157.500° ±0.75° (Tỵ–Bính Palace Border)
#43 Trạch Thiên Quải ䷪ Gua Qi 4 · Period 4	Tuất (294.375°–300.000°) 24-Mtn: Tuất (WNW)	Y1: 294.38°–295.31° Y2: 295.31°–296.25° Y3: 296.25°–297.19°	Y4: 297.19°–298.12° Y5: 298.12°–299.06° Y6: 299.06°–300.00°	Yao 2 (295.313°–296.250°), Yao 5 (298.125°–299.063°)	294.375° ±0.45°, 300.000° ±0.75° (Tuất–Càn Palace Boundary)
#49 Trạch Hỏa Cách ䷰ Gua Qi 4 · Period 8	Tân – Tuất (288.750°–294.375°) 24-Mtn: Tân / Tuất (WNW)	Y1: 288.75°–289.69° Y2: 289.69°–290.62° Y3: 290.62°–291.56°	Y4: 291.56°–292.50° Y5: 292.50°–293.44° Y6: 293.44°–294.38°	Yao 4 (291.563°–292.500°), Yao 5 (292.500°–293.438°)	288.750° ±0.45°, 294.375° ±0.45°
#17 Trạch Lôi Tùy ䷐ Gua Qi 4 · Period 3	Dậu – Tân (277.500°–283.125°) 24-Mtn: Dậu / Tân (W)	Y1: 277.50°–278.44° Y2: 278.44°–279.38° Y3: 279.38°–280.31°	Y4: 280.31°–281.25° Y5: 281.25°–282.19° Y6: 282.19°–283.12°	Yao 1 (277.500°–278.438°), Yao 4 (280.313°–281.250°), Yao 5 (281.250°–282.188°)	277.500° ±0.75° (Dậu–Tân Palace Border), 283.125° ±0.45°
#28 Trạch Phong Đại Quá ䷛ Gua Qi 4 · Period 7	Mùi – Khôn (202.500°–208.125°) 24-Mtn: Khôn (SW)	Y1: 202.50°–203.44° Y2: 203.44°–204.38° Y3: 204.38°–205.31°	Y4: 205.31°–206.25° Y5: 206.25°–207.19° Y6: 207.19°–208.12°	Yao 2 (203.438°–204.375°), Yao 4 (205.313°–206.250°)	202.500° ±0.75° (Mùi–Khôn Palace Border), 208.125° ±0.45°

8. Supreme Hexagram Pairing Laws: Pure One Hexagram, Sum of Ten & Generative Difference of Five

Selecting a single auspicious hexagram for the Sitting Mountain is only 25% of a Xuan Kong Da Gua audit. In Principles of Trigram Pairing, the four spatial pillars of a building—Incoming Dragon (Lai Long 來龍), Sitting Mountain (Tọa Sơn 坐山), Facing Direction (Hướng Thủ 向首), and Water Mouth / Main Gate (Thủy Khẩu / Đại Môn 水口大門)—must lock into mathematical resonance through four classical formulas:

LAW 1 · YI GUA CHUN QING

Pure One Hexagram (Nhất Quái Thuần Thanh 一卦純清)

All four positions share Gua Qi 4 (Yin Metal (He Tu 4–9 Allied Metal))—selecting exclusively from the 8 Upper-Dui hexagrams (#58 Đoài Vi Trạch (䷹), #47 Trạch Thủy Khốn (䷮), #45 Trạch Địa Tụy (䷬), #31 Trạch Sơn Hàm (䷞), #43 Trạch Thiên Quải (䷪), #49 Trạch Hỏa Cách (䷰), #17 Trạch Lôi Tùy (䷐), #28 Trạch Phong Đại Quá (䷛))—or all four positions share Star Period 9 (such as pairing #31 Trạch Sơn Hàm with another Period-9 Parent Hexagram). Zero five-phase friction; pure imperial authority.

LAW 2 · HE SHI (SUM = 10)

Husband-Wife Sum of Ten (Tiên Hậu Thiên Hợp Thập 合十)

Pairs any Upper-Dui hexagram carrying Gua Qi 4 with any hexagram from the Gen Group ☶ (Gua Qi 6 Water · 4 + 6 = 10) (4 + 6 = 10), OR pairs #31 Trạch Sơn Hàm (Period 9) with #58 Đoài Vi Trạch (Period 1) so their Star Periods sum to 9 + 1 = 10! Unlocks complete Yin-Yang communication across the floor plan.

LAW 3 · HE SHENG CHENG (DIFF = 5)

He Tu Generative Difference of Five (Hợp Sinh Thành 合生成)

Pairs any Upper-Dui hexagram carrying Gua Qi 4 with any hexagram from the Qian Group ☰ (Gua Qi 9 Metal · 4 – 9 Allied Metal) (|4 − 9| = 5). Because both groups belong to the exact same He Tu Five Phase (Yin Metal (He Tu 4–9 Allied Metal)), Yang creation and Yin completion merge into one family.

LAW 4 · SAN BAN GUA

Three-Group Parent String (Tam Ban Phụ Mẫu 1-4-7 · 2-5-8 · 3-6-9)

Connects hexagrams along the Jiangdong (1–4–7), Jiangxi (2–5–8), or North-South (3–6–9) strings to circulate Qi across complex multi-wing estates where 180° opposition is blocked by urban topography.

Test your layout against these four laws. Whenever Sitting and Facing share a 180° axis on the Fu Xi Circular Ring, their hexagrams are exact 6-line Yin-Yang inversions of each other—meaning their Upper Trigrams are Early Heaven opposites whose Gua Qi numbers always add up to 10, while their relative line differences remain identical so their Star Period numbers are 100% identical (Pure One Period Qi)! The real art lies in positioning the Main Gate (Đại Môn) and Water Mouth (Thủy Khẩu) so that all four vectors belong to at most two resonant numbers.

9. Period 9 (2024–2043) Field Operations: Direct Spirit (Chính Thần) Mountain & Indirect Spirit (Linh Thần) Water

On February 4, 2024 (Li Chun of the Jia Chen year), the planet crossed the threshold into Lower Cycle Period 9 (2024–2043), governed by Later Heaven Nine Purple Li Fire (九紫離火). In Chính Thần and Linh Thần, the law of Mountain and Water placement in Xuan Kong Da Gua is absolute: “Put Direct Spirit on the Mountain; put Indirect Spirit in the Water” (Chính Thần thượng sơn, Linh Thần hạ thủy 正神上山，零神下水).

How does this law apply specifically to the Dui Group (Lake ☱ · Đoài Cung) between 2024 and 2043?

1. The Lower-Cycle Direct Spirit Group (Chính Thần Đương Vận — Star Periods 6, 7, 8, and above all Period 9): Within the Dui Group (Lake ☱ · Đoài Cung), the supreme Timely Direct Spirit is the 3rd-Generation Parent Hexagram #31 Trạch Sơn Hàm (澤山咸 ䷞) at Khôn (208.125°–213.750°) (carrying Star Period 9 and Gua Qi 4), supported by the Lower-Cycle cohorts #45 Trạch Địa Tụy (Period 6), #62 Lôi Sơn Tiểu Quá (Period 7), and #39 Thủy Sơn Kiển (Period 8). Place high terrain, solid structural backing, the Sitting spine of the building, the CEO throne, and the Master Bed here. Never excavate a deep pool or open a wide low-lying drainage gate on #31 Trạch Sơn Hàm without a secondary water lock, lest you commit “Direct Spirit Falling into Water” (Chính Thần hạ thủy).
2. The Upper-Cycle Indirect Spirit Group (Linh Thần Hợp Thập — Star Periods 1, 2, 3, 4): Because Period 1 + Period 9 = 10, the Pure Root Hexagram #58 Đoài Vi Trạch (兌為澤 ䷹) at Tân – Tuất (283.125°–288.750°) (carrying Star Period 1 and Gua Qi 4) acts as the Supreme Sum-of-Ten Indirect Spirit! Supported by #47 Trạch Thủy Khốn (Period 2), #54 Lôi Trạch Quy Muội (Period 3), and #15 Địa Sơn Khiêm (Period 4), these sectors thrive when activated by open Bright Hall (Minh Đường) plazas, road junctions, main entrance gates, swimming pools, and water mouths.

Figure 4: Period 9 (2024–2043) Mountain and Water operational diagram for the Dui Group (Lake ☱ · Đoài Cung), pairing Direct Spirit #31 Trạch Sơn Hàm with Sum-of-Ten Indirect Spirit #58 Đoài Vi Trạch.

10. Architectural Layout & Three Essentials (Sitting, Facing, Main Gate, Stove, Bed & Water Mouth) + 2026–2027 Audit

How do we translate these compass degrees into concrete architectural drawings for a villa, corporate office, or urban apartment? In Practical Application, we stand at the geometric heart of the floor plan (the Taiji Center—or the center of the main living room/office suite for irregular layouts) and project rays to the five key functional hubs:

Sitting Mountain & Building Spine (Tọa Sơn): Lock the sitting degree onto Yao 2 or Yao 5 of #31 Trạch Sơn Hàm (䷞) (Star Period 9 Direct Spirit) or #45 Trạch Địa Tụy (䷬) (Star Period 6).
Main Entrance Gate & Reception Door (Đại Môn / Nạp Khí Khẩu): Position or angle the main door leaf onto an auspicious Red Yao of #58 Đoài Vi Trạch (䷹) (Star Period 1 → 1 + 9 = 10 Indirect Spirit) or #54 Lôi Trạch Quy Muội (䷵) (Returning Soul wealth retention).
Kitchen Stove & Wealth Alchemy (Táo Vị): Set the stove in a clean sector where its Gua Qi Five Phase either produces or matches the Sitting Mountain's Gua Qi (for Dui Group (Lake ☱ · Đoài Cung) Gua Qi 4 Yin Metal (He Tu 4–9 Allied Metal), pair with Gen Group ☶ (Gua Qi 6 Water · 4 + 6 = 10) or Qian Group ☰ (Gua Qi 9 Metal · 4 – 9 Allied Metal)), while aligning the stove switch/mouth toward a Red Jewel Yao. Strictly avoid placing a fiery stove on Northwest Càn degrees where Fire attacks Heaven's Gate.
Master Bed & Executive Command Desk (Chủ Sàng & Bàn Tổng Giám Đốc): Anchor the bedhead or executive chair in the Micro-Taiji sector of #31 Trạch Sơn Hàm or #39 Thủy Sơn Kiển so the occupant absorbs Timely Lower-Cycle Direct Spirit support.
Water Mouth, Swimming Pool & Drainage Weir (Thủy Khẩu): Ensure incoming water or courtyard fountains sit on #58 Đoài Vi Trạch or #47 Trạch Thủy Khốn, and never allow outgoing drainage to cross a Void Seam.

Figure 5: Practical architectural alignment blueprint from the property's Taiji Center, linking #31 Trạch Sơn Hàm (Sitting), #58 Đoài Vi Trạch (Main Gate), #45 Trạch Địa Tụy (Stove/Vault), and #54 Lôi Trạch Quy Muội (Water Mouth).

Table 4: Architectural Three-Essentials Rating Matrix for the Dui Group (Lake ☱ · Đoài Cung) in Period 9 (2024–2043)
Hexagram	Sitting Spine / Master Bed	Main Gate / Water Mouth	Gua Qi Pairing Formula	Kitchen Stove & Vault Protocol
#58 Đoài Vi Trạch (䷹) Qi 4 · Yun 1	★★☆☆☆ Better for Water/Gate	★★★★★ Supreme 1+9=10 Indirect Spirit	Pair with Gua Qi 6 (Sum of 10) or Gua Qi 4 (Pure One)	Align stove knob to Red Yao; avoid NW Càn Fire Burning Heaven's Gate
#47 Trạch Thủy Khốn (䷮) Qi 4 · Yun 2	★★☆☆☆ Better for Water/Gate	★★★★☆ Strong Upper-Cycle Water	Pair with Gua Qi 6 (Sum of 10) or Gua Qi 4 (Pure One)	Align stove knob to Red Yao; avoid NW Càn Fire Burning Heaven's Gate
#45 Trạch Địa Tụy (䷬) Qi 4 · Yun 6	★★★★☆ Strong Lower-Cycle Sitting	★★★☆☆ Secondary / Pair via Gua Qi	Pair with Gua Qi 6 (Sum of 10) or Gua Qi 4 (Pure One)	Align stove knob to Red Yao; avoid NW Càn Fire Burning Heaven's Gate
#31 Trạch Sơn Hàm (䷞) Qi 4 · Yun 9	★★★★★ Supreme Direct Spirit	★★★☆☆ Secondary / Pair via Gua Qi	Pair with Gua Qi 6 (Sum of 10) or Gua Qi 4 (Pure One)	Align stove knob to Red Yao; avoid NW Càn Fire Burning Heaven's Gate
#39 Thủy Sơn Kiển (䷦) Qi 7 · Yun 8	★★★★☆ Strong Lower-Cycle Sitting	★★★☆☆ Secondary / Pair via Gua Qi	Pair with Gua Qi 3 (Sum of 10) or Gua Qi 7 (Pure One)	Favorable Wood/Fire/Water-bridged hearth on Red Yao
#15 Địa Sơn Khiêm (䷎) Qi 1 · Yun 4	★★☆☆☆ Better for Water/Gate	★★★★☆ Strong Upper-Cycle Water	Pair with Gua Qi 9 (Sum of 10) or Gua Qi 1 (Pure One)	Favorable Wood/Fire/Water-bridged hearth on Red Yao
#62 Lôi Sơn Tiểu Quá (䷽) Qi 8 · Yun 7	★★★★☆ Strong Lower-Cycle Sitting	★★★☆☆ Secondary / Pair via Gua Qi	Pair with Gua Qi 2 (Sum of 10) or Gua Qi 8 (Pure One)	Favorable Wood/Fire/Water-bridged hearth on Red Yao
#54 Lôi Trạch Quy Muội (䷵) Qi 8 · Yun 3	★★☆☆☆ Better for Water/Gate	★★★★☆ Strong Upper-Cycle Water	Pair with Gua Qi 2 (Sum of 10) or Gua Qi 8 (Pure One)	Favorable Wood/Fire/Water-bridged hearth on Red Yao
#43 Trạch Thiên Quải (䷪) Qi 4 · Yun 4	★★☆☆☆ Better for Water/Gate	★★★★☆ Strong Upper-Cycle Water	Pair with Gua Qi 6 (Sum of 10) or Gua Qi 4 (Pure One)	Align stove knob to Red Yao; avoid NW Càn Fire Burning Heaven's Gate
#49 Trạch Hỏa Cách (䷰) Qi 4 · Yun 8	★★★★☆ Strong Lower-Cycle Sitting	★★★☆☆ Secondary / Pair via Gua Qi	Pair with Gua Qi 6 (Sum of 10) or Gua Qi 4 (Pure One)	Align stove knob to Red Yao; avoid NW Càn Fire Burning Heaven's Gate
#17 Trạch Lôi Tùy (䷐) Qi 4 · Yun 3	★★☆☆☆ Better for Water/Gate	★★★★☆ Strong Upper-Cycle Water	Pair with Gua Qi 6 (Sum of 10) or Gua Qi 4 (Pure One)	Align stove knob to Red Yao; avoid NW Càn Fire Burning Heaven's Gate
#28 Trạch Phong Đại Quá (䷛) Qi 4 · Yun 7	★★★★☆ Strong Lower-Cycle Sitting	★★★☆☆ Secondary / Pair via Gua Qi	Pair with Gua Qi 6 (Sum of 10) or Gua Qi 4 (Pure One)	Align stove knob to Red Yao; avoid NW Càn Fire Burning Heaven's Gate

🔥 Urgent Annual Timing Advisory: 2026 (Bing Wu) & 2027 (Ding Wei) Fire Peak

2026 (Bính Ngọ — Heavenly River Water / Double Yang Fire Horse) and 2027 (Đinh Mùi — Heavenly River Water / Yin Fire Goat) represent the blazing solar zenith of early Period 9! During 2026, the Grand Duke (Thái Tuế) sits in Due South Ngọ (172.5°–187.5°, overlapping #40 Jie ䷧ and #44 Gou ䷫) while the Three Killings (Tam Sát)and歲破 Year Breaker occupy Due North Tý (352.5°–7.5°, overlapping #24 Fu ䷗, #2 Kun ䷁, and #23 Bo ䷖). In 2027, Thái Tuế shifts to Mùi (195°–210°, overlapping #12 Pi ䷋ and #28 Da Guo ䷛) while Year Breaker strikes Sửu (15°–30°, overlapping #27 Yi ䷚, #22 Bi ䷕, and #41 Sun ䷨). When groundbreaking or renovating any sector of the Dui Group (Lake ☱ · Đoài Cung) in 2026–2027, never excavate first in the Thái Tuế or Tam Sát mountain; instead, initiate construction in a Sum-of-Ten auspicious sector using a Three-Cycle Xuan Kong Da Gua Date Chart to harmonize the annual spirit.

11. Three-Cycle Xuan Kong Da Gua Date Selection (Ze Ri) & Real-World Field Case Studies

Spatial alignment is the hardware; time is the high-voltage current that brings the circuit to life. In classical San Yuan Xuan Kong Da Gua Date Selection (Huyền Không Đại Quái Trạch Nhật), each of the 60 Jiazi (Lục Thập Hoa Giáp) pillars of Year, Month, Day, and Hour maps to a specific hexagram carrying its own Gua Qi (1–9) and Star Period (1–9). When selecting a date to break ground, install a main gate, set a stove, or move into a property governed by the Dui Group (Lake ☱ · Đoài Cung) (Gua Qi 4 — Yin Metal (He Tu 4–9 Allied Metal)), apply three golden rules:

Rule 1 — Pure One Qi Date Chart (Nhất Quái Thuần Thanh Khóa): All four pillars (Year, Month, Day, Hour) carry Gua Qi 4, matching the Sitting Mountain's Gua Qi 4 so that 5 pillars (4 time pillars + 1 space pillar) vibrate on a single frequency.
Rule 2 — Sum-of-Ten Husband-Wife Date Chart (Tiên Hậu Thiên Hợp Thập Khóa): The four time pillars combine Gua Qi 4 and Gua Qi 6 (4 + 6 = 10), or combine Star Period 9 and Star Period 1 (9 + 1 = 10).
Rule 3 — He Tu Generative Date Chart (Hợp Sinh Thành Khóa): The four time pillars combine Gua Qi 4 and Gua Qi 9 (difference of 5, uniting Yang creation and Yin completion of Yin Metal (He Tu 4–9 Allied Metal)) while ensuring the Day and Hour Gua Qi produce Inward (Sinh Nhập) or assist (Tỷ Hòa) the Sitting Mountain and Householder's Natal Pillar.

FIELD AUDIT #1 · MASTER UNG KHIEM ARCHIVE

Case Study 1: Luxury Aesthetic Clinic & Jewelry Flagship in Thao Dien — Sitting Xian #31 (212.1° Yao 5) with Dui #58 Water Mouth

Beauty, voice, and high-margin luxury belong to Dui ☱. When the founder of a premier aesthetic hospital and diamond flagship in Thao Dien sought my counsel for her new freestanding building, we aligned the main structure to sit at 212.1° inside Yao 5 of #31 Lake Mountain Xian (澤山咸 ䷞: Gua Qi 4 Yin Metal, Star Period 9 Direct Spirit) facing 32.1° inside Yao 5 of #41 Mountain Lake Sun (山澤損 ䷨: Gua Qi 6 Yin Water, Star Period 9). Notice how Mountain and Lake exchange Qi (`Sơn Trạch thông khí`): Sitting Gua Qi 4 + Facing Gua Qi 6 = 10 (Sum of Ten), while both ends share Star Period 9! At the western courtyard (287.2°, Yao 5 of #58 Dui Wei Ze: Gua Qi 4, Period 1), we installed a tiered infinity water basin capturing 1+9=10 Indirect Spirit Qi. Clinic bookings filled three months in advance within 90 days of opening.

FIELD AUDIT #2 · MASTER UNG KHIEM ARCHIVE

Case Study 2: Private Equity Office in Marina Bay, Singapore — Activating #45 Cui (223.5° Yao 5) & #15 Qian (330.4° Yao 5)

Capital flows where hexagram lines are pure. A private equity partnership in Singapore suffered from partner friction and delayed fund closes because their boardroom table straddled the 225.0° Southwest corner void between #45 Cui (䷬) and #50 Ding (䷱). Without touching a single structural curtain wall, we rotated the managing partners' desks and the main boardroom table to 223.5° (Yao 5 of #45 Lake Earth Cui: Gua Qi 4 Metal, Star Period 6—an internal 4+6=10 Sum-of-Ten hexagram of 'Gathering Elite Capital') and oriented the reception entrance inner foyer screen to 330.4° (Yao 5 of #15 Earth Mountain Qian ䷎, 5th Gen of Dui where all six lines are auspicious). The firm closed its USD 180M regional fund four months ahead of schedule.

Measure Your Exact Dui Group ☱ Lake Hexagram & 384-Yao Line on Your Floor Plan

Want to verify which of the 64 Early Heaven Hexagrams and 384 individual lines your home, villa, or corporate headquarters sits on—and whether it locks into Period 9 Direct and Indirect Spirit resonance? Launch Master Ung Khiem's interactive tools now:

☯️ Xuan Kong Da Gua Hub 🧭 Launch Luo Pan Pro (64 Hexagrams & 384 Yao) 🏠 3D Home Feng Shui Simulator

12. Frequently Asked Questions (FAQ) & Classical Bibliography on the Dui Group (Lake ☱ · Đoài Cung)

1. Which 8 hexagrams belong to the Dui Group (Lake ☱ · Đoài Cung) in Xuan Kong Da Gua?

Two complementary sets define this palace. In the Jing Fang 8-Palace transformation lineage (Bát Cung Kinh Phòng), the 8 hexagrams of the Dui Group (Lake ☱ · Đoài Cung) are #58 Đoài Vi Trạch (䷹), #47 Trạch Thủy Khốn (䷮), #45 Trạch Địa Tụy (䷬), #31 Trạch Sơn Hàm (䷞), #39 Thủy Sơn Kiển (䷦), #15 Địa Sơn Khiêm (䷎), #62 Lôi Sơn Tiểu Quá (䷽), #54 Lôi Trạch Quy Muội (䷵). On the San Yuan 360° Upper-Trigram Compass Ring, the 8 hexagrams sharing Dui ☱ as their Upper (Outer) Trigram—all carrying Gua Qi 4 (Yin Metal (He Tu 4–9 Allied Metal))—are #58 Đoài Vi Trạch (䷹), #47 Trạch Thủy Khốn (䷮), #45 Trạch Địa Tụy (䷬), #31 Trạch Sơn Hàm (䷞), #43 Trạch Thiên Quải (䷪), #49 Trạch Hỏa Cách (䷰), #17 Trạch Lôi Tùy (䷐), #28 Trạch Phong Đại Quá (䷛). Notice that the first four hexagrams (Steps 0, 1, 2, and 3) belong to both sets simultaneously!

2. Why do the first 4 hexagrams of the Dui Palace carry Gua Qi 4, while the last 4 change their Gua Qi?

Look at the Outer Trigram. In San Yuan Xuan Kong Da Gua, a hexagram's spatial Gua Qi (1–9) is governed 100% by its Upper (Outer) Trigram. During Jing Fang's first three line transformations (Pure Root #58, 1st Gen #47, 2nd Gen #45, and 3rd Gen #31), only the bottom three lines (Lower Trigram) change, leaving Dui ☱ unchanged on top with Gua Qi 4. Once the transformation climbs into the 4th and 5th lines (4th Gen #39, 5th Gen #15, Wandering Soul #62, and Returning Soul #54), the Upper Trigram changes, shifting their compass Gua Qi while preserving their Dui Palace ancestral soul.

3. Which hexagram in the Dui Group (Lake ☱ · Đoài Cung) is the strongest Sitting Mountain in Period 9 (2024–2043)?

One hexagram stands supreme. The 3rd-Generation Lower-Cycle Parent Hexagram #31 Trạch Sơn Hàm (澤山咸 ䷞) at Khôn (208.125°–213.750°) carries Star Period 9 (Right Assistant / You Bi) and Gua Qi 4. Because its Upper and Lower Trigrams are in total 3-line Yin-Yang opposition, it acts as the reigning Period 9 Direct Spirit (Chính Thần)—ideal for the Sitting Mountain spine, high terrain backing, executive suite, and Master Bed.

4. Which hexagram in the Dui Group (Lake ☱ · Đoài Cung) is best for the Main Gate or Water Mouth in Period 9?

Tap the Pure Root! The doubled hexagram #58 Đoài Vi Trạch (兌為澤 ䷹) at Tân – Tuất (283.125°–288.750°) carries Star Period 1 (Greedy Wolf / Tan Lang) and Gua Qi 4. In Period 9, Star Period 1 forms Sum of Ten (1 + 9 = 10) with the ruling period, making #58 Đoài Vi Trạch the crown Indirect Spirit (Linh Thần) for main gates, water mouths, pools, and road junctions.

5. How do I pair the Dui Group (Lake ☱ · Đoài Cung) using Sum of Ten (He Shi) and Difference of Five (He Sheng Cheng)?

Two mathematical locks govern pairing. For Sum of Ten (He Shi 合十), pair any Upper-Dui hexagram (Gua Qi 4) with any hexagram from the Gen Group ☶ (Gua Qi 6 Water · 4 + 6 = 10) so their Gua Qi numbers add up to 10. For He Tu Generative Difference of Five (He Sheng Cheng 合生成), pair Gua Qi 4 with the Qian Group ☰ (Gua Qi 9 Metal · 4 – 9 Allied Metal) so their Gua Qi numbers differ by 5 and unite within Yin Metal (He Tu 4–9 Allied Metal).

6. How do I avoid Void Lines (Không Vong) when aligning a building to the Dui Group (Lake ☱ · Đoài Cung)?

Never set a centerline on a seam. Each hexagram spans 5.625° and each individual yao line spans 0.9375°. Keep your structural sitting-facing thread at least ±0.75° away from 24-Mountain and 8-Palace borders (Great Void / Đại Không Vong) and at least ±0.45° away from the 5.625° inter-hexagram borders (Small Void / Tiểu Không Vong), aiming squarely for the middle of Yao 2 or Yao 5.

7. Can I apply the Dui Group (Lake ☱ · Đoài Cung) in an apartment where I cannot change the building's exterior orientation?

Yes—through Micro-Taiji angular distribution. Stand at the center of your apartment or main living room with a San Yuan Luo Pan and locate where #31 Trạch Sơn Hàm, #58 Đoài Vi Trạch, and #45 Trạch Địa Tụy fall. Place your bedhead, executive desk, induction stove, and indoor water feature onto those exact 0.9375° Red Jewel Lines, then switch the formation on using a resonant Da Gua Date Selection chart.

8. How do I select an auspicious Xuan Kong Da Gua date for a Dui Group (Lake ☱ · Đoài Cung) property?

Match the Four Pillars of time to the Sitting Mountain's Gua Qi. Convert the Year, Month, Day, and Hour stems and branches into their 64-hexagram Da Gua equivalents, and choose a chart whose four pillars carry Gua Qi 4 (Pure One Qi), Gua Qi 6 (Sum of Ten), or Gua Qi 9 (He Tu Difference of Five), while avoiding annual Thái Tuế and Tam Sát clashes on the Sitting degree.

Classical Sources & Academic References

Grandmaster Yang Yun Song (楊筠松, Tang Dynasty), Qing Nang Ao Yu (青囊奧語 · Green Satchel Mystery Words) & Tian Yu Jing (天玉經 · Heavenly Jade Classic).
Grandmaster Jiang Da Hong (蔣大鴻, Ming–Qing Dynasty), Di Li Bian Zheng (地理辨正 · Rectifying the Canon of Earth Principles).
Jing Fang (京房, Western Han Dynasty), Jing Shi Yi Zhuan (京氏易傳 · Commentary on the Eight-Palace I Ching Transformations).
Shao Yong (邵雍, Northern Song Dynasty), Huangji Jingshi Shu (皇極經世書 · Supreme Principles Governing the World — Fu Xi 64-Hexagram Square & Circular Diagrams).
Anonymous (Ming–Qing San Yuan Transmission), Yu Han Tong Mi (玉函通秘 · Jade Casket Mystery of Xuan Kong Da Gua).
Zeng Zi Nan (曾子南), San Yuan Xuan Kong Da Gua Di Li Jiao Cai (三元玄空大卦地理教材 · Three-Cycle Xuan Kong Da Gua Geomancy Compendium).
Imperially Commissioned Qianlong Compendium (1741), Xie Ji Bian Fang Shu (協紀辨方書 · Treatise on Harmonizing Times and Distinguishing Directions).