Benchmark
Overview
The Scandium Benchmark defines a standard evaluation protocol for ML models trained on the Scandium Dataset. All models report results on the same frozen splits using the same metrics, enabling fair comparison.
Splits
Four split types, all formula-grouped (no same formula across splits), seed=42:
| Split | Train | Val | Test | Tests |
|---|---|---|---|---|
random_80_10_10 |
200,122 | 26,670 | 39,940 | Basic generalization |
composition_held_out |
213,383 | 27,011 | 26,338 | No formula overlap |
family_held_out |
260,984 | 5,165 | 583 | Cross-family generalization |
chemistry_held_out |
227,384 | 26,673 | 12,675 | OOD (all halides as test) |
Metrics
Required
- MAE, RMSE, R² for FE, EaH, BG
- Report per split, per family, per source
Recommended
- ECE (Expected Calibration Error)
- Spearman ρ (ranking correlation)
- F1 for stability classification (EaH < 25 meV)
Baseline Results
Composition-Only Baseline (RF + Ridge on bag-of-elements features)
Results on the random 80/10/10 split, comparing training on the full dataset vs Gold-tier only. See MODEL_LEADERBOARD.md for complete results.
Full Dataset
| Split | FE MAE | FE RMSE | FE R² | EaH MAE | EaH RMSE | BG MAE | BG RMSE |
|---|---|---|---|---|---|---|---|
| random_80_10_10 | 0.392 | 0.572 | 0.791 | 0.224 | 0.414 | 0.494 | 0.863 |
| composition_held_out | 0.390 | 0.547 | 0.801 | 0.223 | 0.376 | 0.497 | 0.861 |
| family_held_out | 0.739 | 0.832 | −1.556 | 0.169 | 0.496 | 1.105 | 1.264 |
| chemistry_held_out | 1.657 | 1.829 | −2.539 | 0.355 | 0.496 | 1.966 | 2.461 |
Gold Tier Only
| Split | FE MAE | FE RMSE | FE R² | EaH MAE | EaH RMSE | BG MAE | BG RMSE |
|---|---|---|---|---|---|---|---|
| random_80_10_10 | 0.298 | 0.424 | 0.854 | 0.024 | 0.028 | 0.762 | 1.077 |
| composition_held_out | 0.306 | 0.439 | 0.838 | 0.024 | 0.028 | 0.772 | 1.091 |
| family_held_out | 0.458 | 0.495 | −3.481 | 0.019 | 0.024 | 0.943 | 1.110 |
| chemistry_held_out | 1.384 | 1.522 | −1.873 | 0.027 | 0.032 | 2.129 | 2.724 |
Key Takeaway
Gold-tier training consistently beats full-dataset training. FE MAE drops from 0.392 → 0.298 on the random split and from 1.657 → 1.384 on the chemistry held-out split, despite having ~3× fewer training examples. This directly validates the tiering system: higher-quality data produces better models even with less data.
Evaluation Runner
# Evaluate predictions on all splits
python benchmark/evaluate.py \
--splits random_80_10_10 composition_held_out \
--predictions predictions.json \
--model-name my_model
# Run baseline
python benchmark/evaluate.py --baseline mean
python benchmark/evaluate.py --baseline median
Leaderboard
See MODEL_LEADERBOARD.md for complete results.