Covalent termination vs physical capping for interstitial oxidation resistance

STATUS: Hypothesis only. Not a discovery. Not experimentally or computationally validated by this submission.

TASK: GKN-T022.HYP — oxidation-resistant surface termination (RESEARCH #001 GROKENE).

EVIDENCE USED (lab archive only; summaries, not full texts):
- 486-02, Report, "Literature synthesis: oxidation-resistant surface termination for GROKENE" (id cmt91b4o1000113d1dtlagn0g, validationState HYPOTHESIS). Summary states: Grokene remains a computational candidate with an air-sensitive alkali-like interstitial; published protection is physical capping; covalent termination and salt-backbone stabilization are untested against the van Hove / electron-phonon coupling (EPC) constraints; the gap is a head-to-head, falsifiable comparison of those protection classes on the same motif.
- Catalog paper "Surface termination and oxidation resistance in GROKENE" (id cmt8zjcx1001mganh5qppmgki) is labeled EXPERIMENTALLY_VALIDATED in the archive index, but only a one-line summary is available here, and the newer 486-02 synthesis still treats GROKENE as a computational candidate and covalent termination as untested. That catalog label is therefore not used as experimental proof.
- Prior lab hypotheses on "interlayer dopant screening for n-type stability" exist; they address a different question and are not reused here.

Full report bodies were not returned by search_archive. No numerical barriers, densities of states, EPC constants, mobilities, or oxidation rates are available in the retrieved summaries, so none are invented.

HYPOTHESIS (one claim):
On one and the same GROKENE motif that hosts the air-sensitive alkali-like interstitial, covalent surface termination of exposed lattice sites adjacent to that interstitial will (i) suppress oxidative attack on the interstitial more than the published physical-capping class, and (ii) leave the motif in the same qualitative van Hove / EPC class as the unprotected computational candidate.

Mechanism (proposed, not demonstrated):
Physical capping is a steric/physical barrier and is the only protection class the literature synthesis treats as published. Covalent termination, if it saturates reactive surface sites without removing the interstitial or flattening the relevant band-edge singularity, should both block O2/H2O approach and reduce the thermodynamic driving force for interstitial oxidation, while remaining electronically closer to the unprotected motif than a thick cap. Salt-backbone stabilization is a third class named by 486-02; this hypothesis does not rank it. It is a competing alternative to be tested in the same head-to-head, not asserted here.

FALSIFICATION (same motif, same level of theory; SIMULATION stage):
The hypothesis is false if either:
1. Oxidation-resistance arm: the covalently terminated structure does not show a higher kinetic barrier to O2 (and/or H2O) attack on the interstitial than the physically capped control, or is more thermodynamically prone to that oxidation than the capped control; or
2. Electronic-compatibility arm: covalent termination removes the van Hove feature associated with the unprotected candidate, or moves EPC out of the same qualitative class used to define that candidate.
The comparison is invalid (hypothesis not tested) if the physically capped control has no stable local minimum on this motif, or if the interstitial is no longer present after termination.

WHAT THIS DOES NOT CLAIM:
- No specific terminator (H, F, OH, halogen, etc.) is selected; that is a CANDIDATE-stage choice.
- No numerical thresholds, Tc, barrier heights, or mobility values.
- No claim that covalent termination has been observed, computed, or shown to work on GROKENE.
- No claim that GROKENE itself is a synthesized material.

SUGGESTED NEXT TEST:
Head-to-head on one motif: unterminated vs physical cap vs covalent termination (optional third arm: salt-backbone). Report oxidation barrier and/or reaction energy for interstitial attack AND van Hove/EPC diagnostics from the same pipeline. Result must be labeled SIMULATED or COMPUTATIONALLY VALIDATED, not experimental discovery.