Imported 2026-09-08. Historical evidence only; claims are not endorsed by V2. This is a local extract, not a link to or dependency on another repository. Original full-file SHA-256: 42e6e5c5cc3dd8eae958cd36b4512770afd3232fbcd6144565aa2069eccd07ef.

Original source lines 262–308

§6. Marginal Exactness: What 6D Chemistry Is

6.1 The theorem ✅

✅ Theorem (marginal exactness of chemistry). Let a system of bound electrons be governed by potentials that separate per Part 8 Lemma 1 — nuclear Coulomb terms supported on the observable coordinates r\mathbf{r}, sector confinement supported on the CP3\mathbb{CP}^3 coordinates ξ\xi — and let OO be any observable supported on the observable coordinates. This covers every chemical probe: energies, geometries, spectra, electric and magnetic response, including the electron–photon vertex (Part 8 §15), since the d=2d=2 coupling acts on shared observable coordinates. Then for product eigenstates ψ⊗χ\psi \otimes \chi,

⟨ψ⊗χa∣O∣ψ′⊗χb⟩=⟨ψ∣O∣ψ′⟩ δab,\langle\psi\otimes\chi_a|O|\psi'\otimes\chi_b\rangle = \langle\psi|O|\psi'\rangle\,\delta_{ab},

so every expectation value and transition amplitude is fixed by the d=3d=3 marginal dynamics alone; the sector factor drops out, and CP3\mathbb{CP}^3-hidden components contribute nothing (Lemma 2). Since the d=3d=3 marginal Hamiltonian is the standard molecular Hamiltonian with IDWT-derived inputs (Part 8 §14.2, §16.1, §17.1), IDWT reproduces standard molecular structure and response theory for every chemistry observable measured by a d=3d=3 apparatus — vibrational and isotopic effects included, since nuclear motion is likewise a d=3d=3 structure. (files/idwt.py STEP 47.)

This is the chemistry-wide form of the Coulomb projection consistency of Part 3 §0.8a: the framework does not disturb tested chemistry. A corollary cuts in the other direction: no chirality, spectroscopy, or kinetics experiment performed with 3D apparatus can deviate from the standard-theory result within the established structure. Proposals of such deviations are not open items — they are excluded.

🔶 Scope condition. The theorem covers the established potentials. Whether the cross-sector kernel contact terms contribute any residue at chemical energy scales is the one stated caveat. §6.3 bounds it.

6.2 What 6D chemistry consists of

Given §6.1, the content of 6D chemistry is three things, none of which is a deviating lab number:

  • Foundation. What standard chemistry postulates, IDWT derives: Pauli exclusion from spinor anticommutation (Part 8 §16.2); the 2L+1 degeneracies, shell counts, and selection rules from the SU(4)⊃SU(3)⊃SO(3)SU(4) \supset SU(3) \supset SO(3) chain and ξ\xi-orthogonality (Part 8 §14.3); the bond mechanism (Part 8 §17); the bond angles from orbit-state orthogonality with the premises derived (§1, §4); the Hückel rule and ring-current scaling (Part 8 §17a, §5). The observed numbers are unchanged; their status changes from axiom to theorem of the sector geometry.
  • Ontology and discriminator. The CP3\mathbb{CP}^3-hidden orbit states exist at every shell L≥1L \geq 1 and are strictly inaccessible to 3D apparatus at any order (Part 8 §14.3, Lemma 2). Standard QM has no counterpart states. Because the inaccessibility is itself a theorem, this is a consistency statement rather than an active test — no 3D experiment can be designed to reach these states, and a measured coupling to one would falsify the d=6d=6 sector identification. The falsifiable content of the framework is carried by its derived numbers — the mass spectrum, mixing angles, δCP\delta_{CP}, Σmν\Sigma m_\nu, and the Part 5 falsifier catalogue — not by new 6D phenomena in chemistry.
  • Frontier. The one place a quantitative residue could appear is the cross-sector kernel contact contribution at chemical scales (§6.1 scope condition); §6.3 bounds it at the 10−1010^{-10} level — nil for all chemistry. Independent of observables, the orbit trajectory geometry in the CP3\mathbb{CP}^3 coordinates (Part 8 §14.4) remains the structural frontier. 6D chemistry is the foundation and the ontology.

6.3 The kernel residue bound 🔶

The scope condition of §6.1 closes in two steps.

✅ Cancellation lemma. Any kernel component supported on the sector factor alone shifts every atomic and molecular state by the same amount: by Lemma 1, all chemistry states of an electron share one sector eigenstate, so the component's expectation is state-independent and cancels in every measurable difference — spectra, bond energies, barriers are all energy differences. Only kernel components with observable-coordinate support can leave a residue.

🔶 Bound on the remainder. The kernel is a contact structure (the colour coupling is its clearest case, Part 3 §0.6; the contact property and the range below are derived from kernel covariance, Part 4 §3.10.1 covariance note and files/idwt.py STEP 59–60), with observable-coordinate range set by the sector length scale: L6=1.414L_6 = 1.414 fm (Part 1 §3e). A contact term of range LL and depth V0V_0 shifts an s-state by ΔE≈V0∣ψ(0)∣2(4π/3)L3\Delta E \approx V_0 |\psi(0)|^2 (4\pi/3)L^3 with ∣ψ(0)∣2=1/(πa03)|\psi(0)|^2 = 1/(\pi a_0^3), and shifts non-s states only at higher order in L/a0L/a_0 (their orbit-state density vanishes at contact). The depth premise: the kernel's entire l=0 output in the d=6d=6 sector is the sector eigenvalue mem_e, so a residual contact piece is bounded by the scale it generates, V0≤meV_0 \leq m_e — a deliberately generous bound. Then

ΔEα2me≤43 ⁣(L6a0)3 ⁣×meα2me=4.8×10−10.\frac{\Delta E}{\alpha^2 m_e} \leq \frac{4}{3}\!\left(\frac{L_6}{a_0}\right)^3\!\times\frac{m_e}{\alpha^2 m_e} = 4.8\times10^{-10}.

The kernel residue on any chemistry observable is at most a few parts in 101010^{10} — the same order as the proton-finite-size correction already catalogued in Part 8 §14.4, three orders below Lamb-scale effects, and far below any chemical measurement. (files/idwt.py STEP 48.)

Consequence. With the cancellation lemma exact and the remainder bounded at 10−1010^{-10}, the §6.1 caveat closes: within the established framework, 6D chemistry has no measurable quantitative residue. Its content is the foundation and the ontology of §6.2. The premise that carries the 🔶 is the depth bound V0≤meV_0 \leq m_e; deriving the actual contact amplitude from the kernel normalization would convert the bound into a value, and is the remaining refinement.

6.4 Kernel contact amplitude: bounded residue, protected fine structure 🔶 / ✅

The §6.3 bound V0≤meV_0 \leq m_e is generous by design. Sharpening it requires the angular content of the (n=13n=13, d=6d=6) electron mode together with the channel structure of the hidden-state self-energy.

Angular content of the electron mode. The mode index counts levels from the ground state: S(1,d)=1S(1,d) = 1 is the single level-0 state, so mode nn sits at oscillator level N=n−1N = n-1 (the convention of Part 7 §1.2 and the Dirac spectral count of Part 8 Theorem S1). The free d=6d=6 mode carries no intrinsic angular momentum: a flat R6\mathbb{R}^6 sector has rotation group SO(6)≅Spin(6)≅SU(4)\mathrm{SO}(6) \cong \mathrm{Spin}(6) \cong SU(4), and the mode's content is the harmonic tower Hm=(0,m,0)H_m = (0,m,0) over the occupied levels (files/idwt.py STEP 82). The rotation-invariant contact component is the SO(6)\mathrm{SO}(6) singlet H0H_0, present exactly when N=n−1N = n-1 is even, that is when nn is odd. The electron, n=13n = 13, is odd, so the contact harmonic is present: the kernel's contact piece has a nonzero matrix element with the electron mode, and the contact amplitude is not removed by parity. The residue stays at the §6.3 value, ΔE≤4.8×10−10\Delta E \leq 4.8\times10^{-10} hartree — far below any chemical measurement, so the §6.1 scope condition closes at the bounded level: 6D chemistry carries no measurable quantitative residue. The precise contact value reduces to a bound-state perturbation sum: an SO(3)SO(3) angular momentum is defined only once the nucleus anchors the observable rotation SO(3)obs⊂SO(6)SO(3)_{\rm obs} \subset SO(6) in the bound problem (files/idwt.py STEP 81), where the contact piece couples through the s-channel.

Angular selection on the higher multipoles (✅). The l≠0l \neq 0 components of the electron mode do not shift a spherically symmetric (s-type) atomic orbital: ∫∣ψs(r)∣2Ylm(θ,φ) dΩ=0\int |\psi_s(\mathbf{r})|^2 Y_l^m(\theta,\varphi)\,d\Omega = 0 for l≠0l \neq 0. The even multipoles l=2,4,…l = 2, 4, \ldots act only through orbital anisotropy; the l=0l = 0 piece is the one carrying the §6.3-bounded contact shift.

Fine structure is protected by a selection rule, not only by smallness (✅). The second-order self-energy of an observable state through the CP3\mathbb{CP}^3 hidden states decomposes by which coordinates the kernel touches, and only one of the three channels can affect fine structure. The pure-sector channel (kernel identity on the d=3d=3 marginal) has an orbital-independent energy denominator by the Lemma 1 separability, so it produces a shift identical for every orbital — an exact common shift that cancels in every measurable difference by the §6.3 cancellation lemma. The d=3d=3-only channel is diagonal in the sector index and has zero observable↔\leftrightarrowhidden matrix element (Lemma 2), contributing nothing. The mixed observable×\timessector channel is the only orbital-dependent one; it carries the contact factor L6/a0L_6/a_0 at each of two vertices and is therefore (L6/a0)2≈7.1×10−10(L_6/a_0)^2 \approx 7.1\times10^{-10}, an estimate of order 10−1910^{-19} hartree — nine orders below the Lamb shift. Fine structure is protected by the selection rule — the pure-sector self-energy cancels, the d=3d=3-only channel cannot reach the hidden states — and not only by the smallness of the contact factor (files/idwt.py STEP 77). The relevant SO(3)SO(3) for this channel is the nucleus-anchored observable rotation SO(3)obs⊂SO(6)≅SU(4)SO(3)_{\rm obs} \subset SO(6) \cong SU(4) of the bound problem (files/idwt.py STEP 81) — so the explicit value of the mixed channel reduces to the perturbation sum over its multiplicities.

The electron's sector content and its chemistry orbitals are different objects. The electron mode index ne=13n_e = 13 arises from the seed decomposition ne=nν1+nup=10+3=13n_e = n_{\nu_1} + n_{\rm up} = 10 + 3 = 13 (Part 2 §2, §6), placing the mode at level N=12N = 12, whose content includes the SO(6)\mathrm{SO}(6)-singlet contact component (nn odd); S(13,6)=18564S(13,6) = 18564 sets the d=6d=6 mass quantum mscale,6=me/18564m_{\rm scale,6} = m_e/18564. The periodic-table orbitals (s, p, d, f) are bound states of the d=3d=3 marginal Coulomb problem (Marginal Exactness, §6.1), not the harmonic content of this single sector mode; the two are not to be identified.