benchmarks/materials/matbench_mp_e_form/data/README.md

matbench_mp_e_form — data file

Usage

bash download.sh   # writes data.csv in this directory

Requires: python3 (stdlib only — json, gzip, csv, collections) and curl. No third-party packages needed. The script downloads the raw Matbench JSON (~166 MB compressed) via curl, extracts element mole fractions from the embedded pymatgen Structure objects, and writes data.csv. Runtime: ~2–5 min depending on connection.

data.csv is gitignored per the repo-wide rule (benchmarks/**/data/data.* in .gitignore) — always rebuild locally with this script. Only this README.md is kept in git.

Source

Field	Value
Dataset	Matbench v0.1 — matbench_mp_e_form
URL	https://ml.materialsproject.org/projects/matbench_mp_e_form.json.gz
License	MIT (Matbench) / CC-BY-4.0 (Materials Project)
Paper	Dunn et al., npj Computational Materials 6, 138 (2020)
DOI	https://doi.org/10.1038/s41524-020-00406-3
Retrieved	2026-04-22

The formation energy values were computed by the Materials Project using high-throughput VASP (PBE+U / PAW) DFT calculations. Formation energy per atom (e_form) is defined as the energy of the compound minus the energies of its constituent elements in their standard reference states, divided by the number of atoms. Negative values indicate thermodynamically stable compounds.

Column layout

Column 0 is the output. Columns 1–84 are element mole fractions derived from the crystal structure (sum to 1.0 per row; absent elements are 0.0).

Col	Name	Units	Role
0	e_form	eV/atom	output
1	frac_Ac	dimensionless	input
2	frac_Ag	dimensionless	input
3	frac_Al	dimensionless	input
4	frac_As	dimensionless	input
5	frac_Au	dimensionless	input
6	frac_B	dimensionless	input
7	frac_Ba	dimensionless	input
8	frac_Be	dimensionless	input
9	frac_Bi	dimensionless	input
10	frac_Br	dimensionless	input
11	frac_C	dimensionless	input
12	frac_Ca	dimensionless	input
13	frac_Cd	dimensionless	input
14	frac_Ce	dimensionless	input
15	frac_Cl	dimensionless	input
16	frac_Co	dimensionless	input
17	frac_Cr	dimensionless	input
18	frac_Cs	dimensionless	input
19	frac_Cu	dimensionless	input
20	frac_Dy	dimensionless	input
21	frac_Er	dimensionless	input
22	frac_Eu	dimensionless	input
23	frac_F	dimensionless	input
24	frac_Fe	dimensionless	input
25	frac_Ga	dimensionless	input
26	frac_Gd	dimensionless	input
27	frac_Ge	dimensionless	input
28	frac_H	dimensionless	input
29	frac_Hf	dimensionless	input
30	frac_Hg	dimensionless	input
31	frac_Ho	dimensionless	input
32	frac_I	dimensionless	input
33	frac_In	dimensionless	input
34	frac_Ir	dimensionless	input
35	frac_K	dimensionless	input
36	frac_La	dimensionless	input
37	frac_Li	dimensionless	input
38	frac_Lu	dimensionless	input
39	frac_Mg	dimensionless	input
40	frac_Mn	dimensionless	input
41	frac_Mo	dimensionless	input
42	frac_N	dimensionless	input
43	frac_Na	dimensionless	input
44	frac_Nb	dimensionless	input
45	frac_Nd	dimensionless	input
46	frac_Ni	dimensionless	input
47	frac_Np	dimensionless	input
48	frac_O	dimensionless	input
49	frac_Os	dimensionless	input
50	frac_P	dimensionless	input
51	frac_Pa	dimensionless	input
52	frac_Pb	dimensionless	input
53	frac_Pd	dimensionless	input
54	frac_Pm	dimensionless	input
55	frac_Pr	dimensionless	input
56	frac_Pt	dimensionless	input
57	frac_Pu	dimensionless	input
58	frac_Rb	dimensionless	input
59	frac_Re	dimensionless	input
60	frac_Rh	dimensionless	input
61	frac_Ru	dimensionless	input
62	frac_S	dimensionless	input
63	frac_Sb	dimensionless	input
64	frac_Sc	dimensionless	input
65	frac_Se	dimensionless	input
66	frac_Si	dimensionless	input
67	frac_Sm	dimensionless	input
68	frac_Sn	dimensionless	input
69	frac_Sr	dimensionless	input
70	frac_Ta	dimensionless	input
71	frac_Tb	dimensionless	input
72	frac_Tc	dimensionless	input
73	frac_Te	dimensionless	input
74	frac_Th	dimensionless	input
75	frac_Ti	dimensionless	input
76	frac_Tl	dimensionless	input
77	frac_Tm	dimensionless	input
78	frac_U	dimensionless	input
79	frac_V	dimensionless	input
80	frac_W	dimensionless	input
81	frac_Y	dimensionless	input
82	frac_Yb	dimensionless	input
83	frac_Zn	dimensionless	input
84	frac_Zr	dimensionless	input

Dataset statistics (after download)

• Rows: 132,752
• Columns: 85 (1 output + 84 element fraction inputs)
• Distinct elements: 84
• Output range: approximately [-4.6121, 2.4995] eV/atom (formation energy per atom)
• Output mean: ~-1.4079 eV/atom
• Output median: ~-1.3971 eV/atom
• No missing values (element fractions are 0.0 for absent elements)