Hub folder	Training target	Intended use
`product-sft/`	Complete target PSMILES	Property-conditioned polymer generation baseline
`fragment-sft/`	Single-cut replacement fragment	Experimental source-constrained fragment generation

These folders are independent Transformers checkpoints and each includes model weights, tokenizer, generation configuration, training arguments, and training metadata.

Loading a checkpoint

python

from transformers import AutoModelForSeq2SeqLM, AutoTokenizer

repo_id = "luca0621/polyedit-reactiont5-egc"
tokenizer = AutoTokenizer.from_pretrained(repo_id, subfolder="product-sft")
model = AutoModelForSeq2SeqLM.from_pretrained(repo_id, subfolder="product-sft")

PolyEdit task strings must be processed with the sentinel-token escape map stored in training_meta.json. The project helper polyedit.reactiont5.encode_for_tokenizer performs this conversion and decode_from_tokenizer reverses it.

Product-SFT checkpoint

The model receives a source PSMILES, source Egc, and requested Egc interval and generates a complete product PSMILES. Evaluation uses five deterministic beams and a train-only fingerprint property reranker.

On the frozen 31,756-request test split:

Metric	Result
Valid selected product	98.29%
DFT-evaluable selection	86.32%
DFT success given evaluable	33.96%
Overall DFT-verified yield	29.32%
Exact target selected	1 / 31,756
Audited source-edit plus property success	2 / 31,756

The 29.32% result is a property-conditioned generation metric. It does not mean that the output is a valid single-step edit of the supplied source.

Weight SHA-256:

2a14f5fce517bbad16ec79667e094096c51e338a7a1f0d75e174719f60eaf6f5

Fragment-SFT checkpoint

The fragment model was trained on 15,016 train examples from source/target pairs sharing a valid two-anchor single-cut context. It predicts only the target replacement fragment. Generated fragments must be applied to the source through the PolyEdit executor; they are not complete polymer products.

Train fragment classes: 405
Validation examples: 232
Best reported validation loss: 0.7923
Training epochs: 5

Open-ended fragment beam decoding remained weak. The best source-constrained benchmark result in the project uses a closed-vocabulary fragment ensemble and site ranker, not this checkpoint.

Weight SHA-256:

686a3c99c86ca99df4861631fd8a4c513ac3da23a16049291a77f02784b7e081

DFT metric caveat

No new quantum-chemistry calculation is run during evaluation. A generated product is DFT-evaluable only when its PolymerGraphID has a frozen Egc value in labeled_mmp_pairs.csv. Outputs without a frozen label are unknown, not confirmed failures. Always report DFT coverage together with conditional success and overall verified yield.

One duplicated polymer has conflicting Egc labels (3.8424 and 4.7875 eV), affecting 174 requests. The project audit document reports both the raw 31,756-request metrics and a clean 31,582-request view that excludes this conflict.

Scope and limitations

Property: Egc only
Split: leakage-safe MMP connected components, seed 42
The product checkpoint is a generator baseline, not a guaranteed editor.
The fragment checkpoint requires the PolyEdit source executor.
Rule-SFT checkpoints that failed executable-rule evaluation are intentionally not published here.