SOURCE_SNAPSHOTS.md

Source Snapshots

This file records the exact extraction dates and versions for each data source, ensuring reproducibility of the Scandium Dataset.

Materials Project

Field	Value
API version	MPRester v3.1
Extraction date	2026-07-20
API endpoint	https://api.materialsproject.org/
Filter	chemsys includes Li, Na, Mg, Ca, Zn, Al, K
Fields	material_id, formula_pretty, structure, formation_energy_per_atom, energy_above_hull, band_gap, total_magnetization, volume, density, symmetry, is_stable
Entries	69,279
License	CC BY 4.0
Reference	Jain et al., APL Materials, 2013

OQMD

Field	Value
API	jarvis-tools data("oqmd_3d_no_cfid")
Extraction date	2026-07-20
Dataset version	OQMD v1.4 (no_cfid variant)
Entries	171,780
License	Non-commercial + attribution
Reference	Saal et al., JOM, 2013; Kirklin et al., npj Comp. Mater., 2015
Known issues at extraction	Coordinate artifacts (137,405 entries), missing space groups (171,764 entries), zero volumes (47,807 entries) — all repaired in pipeline

JARVIS-DFT

Field	Value
API	jarvis-tools data("dft_3d")
Extraction date	2026-07-20
Dataset version	JARVIS-DFT 2024 (dft_3d subset)
Entries	25,673
License	CC0 (Public Domain)
Reference	Choudhary et al., npj Comp. Mater., 2020
Known issues at extraction	No energy_above_hull (by design — JARVIS does not compute convex hull distance)

Reproducibility Notes

To reproduce the dataset from scratch:

1. MP entries: Run scripts/audit_phase1_raw_data.py with your MP API key
2. OQMD entries: Run the same script — it fetches via jarvis-tools
3. JARVIS entries: Also fetched via jarvis-tools in the same script
4. Repair pipeline: Run scripts/audit_phase2_structure.py through scripts/audit_phase6_quality.py in sequence
5. Final assembly: Run scripts/fix_dataset_v3.py

Due to source redistribution policies, the raw downloaded files are not included in the repository. The download scripts must be run by the user with appropriate API credentials.