# NexaMat Archived Project Record

Project: NexaMat / NexaMat2  
Status: Archived and on ice indefinitely; model shipped as a qualified research and candidate-generation artifact  
Archive date: 2026-07-24  
Model hub: `https://huggingface.co/AethronPhantom/Nexa_Mat2`  

## Purpose

NexaMat is a compact materials model stack for proposing and evaluating inorganic
crystal candidates. The project recovered a diffusion decoder that initially
produced very low-yield geometry into a useful native, no-repair candidate
generator across six non-alloy inorganic profiles. It then investigated the
harder problem of repeatable metastable generation.

## Shipped Claim

The shipped model is suitable for:

- profile-conditioned native inorganic candidate generation;
- auditable candidate filtering and ranking;
- chemistry-aware proposal workflows using the frozen physics encoder;
- research, screening, and application prototyping where external relaxation
  and stability evaluation remain mandatory.

The shipped model is not claimed to be:

- a high-yield metastable or SUN/MSUN generator;
- a replacement for relaxation, DFT, MLIP, or hull evaluation;
- a universally validated generator for alloys, organics, MOFs, polymers, or
  molecular crystals;
- directly comparable to MatterGen under an identical public stability protocol.

## Canonical Model State

| Component | Parameters | Role | Status |
| --- | ---: | --- | --- |
| Physics encoder | 2,813,714 | Plausibility and physics grounding | Shipped, frozen |
| Diffusion decoder | 1,248,145 | Native atom, coordinate, and lattice proposal | Shipped |
| Full compact stack | 4,061,859 | Encoder plus decoder | Shipped |
| Multimodal controller | Separate 14B pilot | Evidence routing and explanation | Optional, partial pilot |

The production decoder lineage is the recovered V78 native checkpoint. V90 is
an evaluation artifact produced from a provided checkpoint; its recorded run
prefix does not contain a trainable `best_diffusion_checkpoint.pt`. Later
V26-V36 conservative-field experiments are archived as research evidence and
must not be substituted for the shipped native decoder.

## Final Scientific State

- Static native generation: useful and production-tolerable on SSB, battery,
  oxide, halide/chalcogenide, semiconductor, and broad-inorganic profiles.
- Novelty: 100% in the final six-profile static suite.
- Best bounded metastability anchor: one prior 64-candidate test reported 2/64
  M.S.U.N. candidates and mean evaluated `e_above_hull = 0.8750 eV/atom`.
  Individual candidates reached 0.1786 and 0.1837 eV/atom. Those examples show
  that NexaMat can reach approximately 0.18 eV/atom; they do not mean its
  typical output lies at 0.18 eV/atom.
- Repeatability: not fully verified. The same prior test converged only 3/64
  structures at the strict relaxation threshold, and later cohorts did not
  establish reliable recurrence. Its historical 2/64 result is evidence of
  capability, not a current production-rate estimate. It was also well below
  the intended 25-50% yield.
- Final campaign verdict: meaningful partial progress followed by a scientific
  plateau. The project was paused because the campaign had dragged on for weeks
  and the remaining reliability gap no longer justified continuous iteration,
  not because the model had no useful metastable support.

## Canonical Documents

1. `ARCHIVE_CLOSEOUT_2026-07-24.md`
2. `results/papers/NEXA_MAT_FINAL_PROJECT_COMPENDIUM_2026-07-24.md`
3. `results/papers/NEXA_MAT_FINAL_TECHNICAL_PAPER_2026-07-24.md`
4. `results/papers/NEXA_MAT_FINAL_MODEL_CARD_2026-07-24.md`
5. `results/papers/NEXA_MAT_ALIGNMENT_PIPELINE_KNOWLEDGE_PAPER.md`
6. `results/papers/NEXA_MAT_METASTABLE_ARCHITECTURE_AND_TRAINING.md`
7. `results/benchmarks/2026-07-24_foundation_residual_metastability_closeout.md`

## Reopen Contract

If the project is resumed, do not restart with another static-validity,
force-loss, router, adapter, or controller sweep. First reproduce the July 2
low-hull anchor from the exact checkpoint, sampler, seeds, candidate rows,
relaxer, and hull evaluator. If it reproduces, train a mathematically matched
low-hull endpoint generator and measure recurrence density. If it does not,
classify the result as lineage or evaluator drift before changing the model.

The curated shippable model surface and public evidence are preserved in this
Hugging Face repository. Private experiment history remains separately
archived. The project is on ice indefinitely, not abandoned; the retained
artifacts are sufficient to support a controlled restart if the stability work
becomes worthwhile again.