Triaging hypothetical crystals for stability
Classify 215,488 hypothetical crystals as stable or not against a fixed DFT convex hull, scored by F1.
| 1 | # Triaging hypothetical crystals for stability |
| 2 | |
| 3 | High-throughput materials search invents far more candidate crystals than anyone can afford to validate with |
| 4 | density functional theory. This benchmark asks a model to look at more than 200,000 unrelaxed hypothetical structures |
| 5 | and say which ones are thermodynamically stable, so that the expensive calculations can be spent on the right ones. |
| 6 | |
| 7 | ## Task |
| 8 | |
| 9 | For each structure in the WBM test set, predict its energy and classify it as stable, meaning it lies on or below |
| 10 | the Materials Project convex hull, or unstable. The hull is fixed: it is built from the Materials Project's own |
| 11 | DFT entries as queried on 2023-02-07 (release v2022.10.28). Models may use any training data; the site's |
| 12 | "Compliant models" filter shows only open models trained exclusively on Materials Project-anchored data. |
| 13 | The headline score is the $F_1$ of the stable class, the harmonic mean of precision and recall. Most entries are |
| 14 | machine-learning force fields that relax each structure first and then read off its energy, the protocol the site |
| 15 | labels IS2RE-SR. |
| 16 | |
| 17 | ## Background |
| 18 | |
| 19 | The test structures come from Wang, Botti and Marques, who generated 257,487 candidates by repeated |
| 20 | chemically-similar element substitution on Materials Project crystals, in five rounds, and relaxed them all with |
| 21 | Materials Project-compatible DFT settings. Riebesell and co-workers turned that into a benchmark in 2023: because |
| 22 | the substitutions move progressively away from the training distribution, the set measures extrapolation rather |
| 23 | than interpolation, and because the metric is a classification score it reflects what a screening campaign |
| 24 | actually cares about, which is the hit rate among the candidates it chooses to compute. |
| 25 | |
| 26 | ## Data and evaluation |
| 27 | |
| 28 | - Data: the WBM test set and the Materials Project reference energies, as registered files on figshare |
| 29 | (<https://figshare.com/articles/dataset/22715158>) and fetched by the `matbench_discovery` package. After |
| 30 | cleaning, 256,963 structures remain of the 257,487 generated. |
| 31 | - Split: there is no cross-validation; the whole WBM set is the test set. The default leaderboard view is the unique-prototype subset, 215,488 structures |
| 32 | left after removing prototypes that already occur in the Materials Project and keeping only the lowest-energy |
| 33 | structure per prototype; the full set is the other view. |
| 34 | - Metric: $F_1$ for the stable class, higher is better. The site also reports discovery acceleration factor, |
| 35 | precision, recall, energy MAE and $R^2$, and a combined score CPS that weights $F_1$ at 50%, phonon |
| 36 | $\kappa_{\mathrm{SRME}}$ at 40% and geometry-optimisation RMSD at 10%. |
| 37 | - Official evaluation code: <https://github.com/janosh/matbench-discovery> (MIT); a model is submitted as a pull |
| 38 | request with its predictions and a metadata file. The data files on figshare are CC BY 4.0. |
| 39 | |
| 40 | ## What is known |
| 41 | |
| 42 | - Top of the leaderboard on unique prototypes: EquiformerV3+DeNS-OAM at $F_1 = 0.931$, with TECE-OAM-RRA-1.0 and |
| 43 | EquFlashV2 at 0.929 and Prophet-OAME-MBD at 0.928. The four are within 0.003 of each other. |
| 44 | - Prophet-OAME-MBD leads the combined score at CPS 0.912, mostly on the strength of its phonon term. |
| 45 | - The first generation of universal potentials is far behind: MACE-MP-0 at 0.669, CHGNet at 0.613 and M3GNet |
| 46 | at 0.569. |
| 47 | Much of the gain since then came from training data: the same architecture trained on OMat24 and Alexandria |
| 48 | gains sharply over its MPtrj-only variant, for example eSEN-30M at 0.925 against 0.831. |
| 49 | - The best compliant model, EquiformerV3+DeNS-MP, is trained only on MPtrj and reaches $F_1 = 0.863$, so part of |
| 50 | the gap at the top reflects training data rather than method. |
| 51 | |
| 52 | ## What would count as progress |
| 53 | |
| 54 | - An $F_1$ above 0.931 on the unique-prototype set under the official protocol, submitted with the prediction |
| 55 | files so precision, recall and the energy metrics can be recomputed. |
| 56 | - A compliant model above 0.863, trained only on Materials Project-anchored data, which isolates the method from |
| 57 | the data. |
| 58 | - Code and a checkpoint that reproduce the run, plus the geometry and phonon metrics, since a model that wins on |
| 59 | $F_1$ alone can still fail the combined score. |
| 60 | |
| 61 | ## References |
| 62 | |
| 63 | 1. J. Riebesell, R. E. A. Goodall, P. Benner et al., "A framework to evaluate machine learning crystal stability |
| 64 | predictions", *Nature Machine Intelligence* **7**, 836–847 (2025). <https://doi.org/10.1038/s42256-025-01055-1> |
| 65 | 2. H.-C. Wang, S. Botti and M. A. L. Marques, "Predicting stable crystalline compounds using chemical |
| 66 | similarity", *npj Computational Materials* **7**, 12 (2021). <https://doi.org/10.1038/s41524-020-00481-6> |
| 67 | 3. A. Jain et al., "The Materials Project: A materials genome approach to accelerating materials innovation", |
| 68 | *APL Materials* **1**, 011002 (2013). <https://doi.org/10.1063/1.4812323> |
| 69 | 4. B. Póta, P. Ahlawat, G. Csányi and M. Simoncelli, "Thermal Conductivity Predictions with Foundation Atomistic |
| 70 | Models" (2024), the source of the $\kappa_{\mathrm{SRME}}$ term in CPS. <https://arxiv.org/abs/2408.00755> |
| 71 | |
| 72 | ## Source |
| 73 | |
| 74 | Imported from [Matbench Discovery, crystal stability](https://matbench-discovery.materialsproject.org/benchmarks/discovery), curated by Janosh Riebesell et al. Open according |
| 75 | to the source as of 2026-10-20. The statement above is written in our own words; see the source for the original |
| 76 | wording, history and discussion. |