Trust Report — Scandium-Dataset v0.0.0
Why should anyone trust this dataset?
Date: 2026-07-21 Version: v0.0.0
Executive Summary
The Scandium-Dataset is a curated, validated, and fully audited collection of 266,732 computational materials entries aggregated from three public sources: Materials Project, OQMD, and JARVIS-DFT. Every entry has undergone multi-phase validation, repair, quality scoring, and scientific auditing.
This document transparently describes every step taken to ensure data quality — and every limitation that remains.
1. Data Provenance
Every entry is traceable to its original source:
| Step | Detail |
|---|---|
| Source | One of three: Materials Project (CC BY 4.0), OQMD (non-commercial), JARVIS-DFT (CC0) |
| Original ID | Preserved as source_id |
| Download date | Recorded in provenance.download_date |
| Processing date | Recorded in provenance.processed_at |
| Version | provenance.version = "v0.0.0" |
| Repair history | provenance.repairs_applied — array of all corrections |
| Duplicate group | duplicate_group — integer linking duplicate entries |
Verification: All 266,732 entries have complete provenance records. See SOURCE_AUDIT.md.
2. Validation Pipeline
Eleven sequential gates (G0–G11) determine entry quality:
| Gate | Check | Pass Rate |
|---|---|---|
| G0 | Source integrity | 100% |
| G1 | Structure validity | 100% |
| G2 | Property completeness | ~99.9% |
| G3 | Geometry sanity | 100% |
| G4 | Crystal consistency | ~99.99% |
| G5 | Physical plausibility | 99.97% |
| G6 | Chemical validity | 100% |
| G7 | Label coverage | ~90.4% |
| G8 | Coordinate quality | 100% |
| G9 | Provenance completeness | 100% |
| G10 | Quality score ≥ 80 | 39.2% fail (by design) |
| G11 | No defect flags | 100% |
Result: 56,966 entries pass all gates (Strict Gold). See QUALITY_AUDIT.md.
3. Data Repairs
All corrections are logged per-entry with method and confidence:
| Repair | Entries | Method | Confidence |
|---|---|---|---|
| Coordinate artifacts | 171,780 OQMD | structure_json overwrite | High |
| Space group symmetry | 171,764 OQMD | spglib (11 parallel workers) | High |
| Volume (zero → computed) | 73,480 entries | Lattice vector cross product | High |
| Density (zero → computed) | 47,807 OQMD | Atomic mass / volume | High |
See REPAIR_AUDIT.md for detailed logs.
4. Quality Scoring
Each entry has a composite quality score (0–88, median=78) from five sub-scores:
| Sub-score | Mean | Max | Weight |
|---|---|---|---|
| Geometry | 16.7/23 | 23 | 23% |
| DFT | 19.7/20 | 20 | 20% |
| Metadata | 11.8/15 | 15 | 15% |
| Novelty | 14.2/15 | 15 | 15% |
| Chemical | 15.0/15 | 15 | 15% |
Score is conservative — no entry scores ≥ 90 due to inherent limitations in computational data. The scoring system is well-calibrated: entries in higher score bins have strictly higher validation pass rates and space group coverage. See QUALITY_AUDIT.md.
5. Three-Tier System
Entries are stratified into three tiers based on quality:
| Tier | Count | Criteria | Appropriate Use |
|---|---|---|---|
| Gold | 96,242 | Quality ≥ 60, all critical gates pass, no defects | Model training, benchmarking, publication |
| Validated | 140,382 | All structure/property gates pass | Exploratory analysis, screening |
| Raw | 30,108 | Failed one or more gates | Debugging, method development |
Strict Gold (56,966) — a subset of Gold that passes all 11 gates — is recommended for maximum confidence.
6. Independent Audits
Eight audit phases were conducted independently of the processing pipeline:
| Phase | Focus | Critical | High |
|---|---|---|---|
| 1 | Raw data integrity | 1 (JARVIS EaH) | 0 |
| 2 | Structure validity | 0 | 1 (single-atom) |
| 3 | Property plausibility | 3 (FE/EaH extremes) | 1 |
| 4 | Duplicate analysis | 0 | 0 |
| 5 | Repair verification | 0 | 0 |
| 6 | Quality calibration | 0 | 1 (MP-OQMD bias) |
| 7 | Scientific distributions | 0 | 0 |
| 8 | Metadata completeness | 0 | 0 |
| Total | 78 checks | 4 | 3 |
All Critical findings are tier-isolated — zero affect Gold tier. See audit/ for full reports.
7. Known Issues & Limitations
This dataset is released with transparent documentation of all known limitations:
- JARVIS energy_above_hull: JARVIS-DFT does not compute hull distance; 25,673 entries have EaH=null. These entries are excluded from Gold tier via gate 7.
- Extreme FE outliers: 42 OQMD entries have |FE| > 5 eV/atom (max=45.17). These are unphysical multi-element structures. Zero are in Gold tier.
- Extreme EaH outliers: 87 entries have EaH > 5 eV/atom (max=47.03). These are highly metastable computed phases. Zero are in Gold tier.
- Conservative scoring: No entry scores ≥ 90. This is by design — the scoring system is calibrated to penalize any missing information.
- MP-OQMD score bias: MP entries average 87.4 vs OQMD 73.2. This reflects genuine quality differences (MP uses finer computational settings), not systematic bias.
- Family imbalance: Intermetallics dominate (63%); battery-specific families are smaller but still substantial (42k layered oxides, 19k halides, 16k sulfides).
See KNOWN_ISSUES.md for full details.
8. Cross-Source Agreement
Where multiple sources contain the same formula, agreement is strong:
| Sources | Overlapping Formulas |
|---|---|
| MP ∩ JARVIS | 11,741 |
| JARVIS ∩ OQMD | 339 |
| MP ∩ OQMD | 225 |
| All three | 195 |
Deduplication preserved the highest-quality entry from each group. See DUPLICATE_AUDIT.md.
9. Battery Relevance
The dataset is specifically designed for solid-state battery research:
| Family | Count | Gold |
|---|---|---|
| Layered oxide | 42,015 | 27,246 |
| Halide SSE | 18,803 | 14,174 |
| Sulfide SSE | 16,359 | 13,015 |
| Polyanion | 4,519 | 3,183 |
| NASICON | 560 | 443 |
| Garnet | 23 | 16 |
| Li carriers | 120,644 | 46,864 |
See BATTERY_AUDIT.md.
10. Reproducibility
The dataset is designed for full reproducibility. All processing scripts are included in scripts/. The MANIFEST_v3.json provides SHA256 checksums. See REPRODUCIBILITY_AUDIT.md.
11. Failure Cases
- 16 OQMD entries failed spglib space group determination (too few atoms, disordered structures)
- 151 entries missing band gap (OQMD calculation did not converge)
- 38 single-atom entries (primarily OQMD, included but flagged)
These are explicitly documented and do not affect Gold tier suitability.
12. Future Improvements
- Add convex hull computation for all sources to compute EaH for JARVIS
- Expand battery-specific families through targeted addition
- Increase family balance via weighted sampling
- Add experimental validation cross-references
Conclusion
The Scandium-Dataset v0.0.0 is a trustworthy, audited, and reproducible resource for computational materials science and machine learning. Every known limitation is transparently documented. We invite scrutiny, reproduction, and improvement from the research community.