license: cc-by-4.0
language:
- en
tags:
- materials-science
- out-of-distribution-detection
- graph-neural-networks
- benchmark
pretty_name: MOOD - Materials Out-of-Distribution Detection
configs:
- config_name: default
description: All retained (dataset, architecture, split) settings.
MOOD: Materials Out-of-Distribution Detection Benchmark
Pre-extracted graph neural network embeddings, trained checkpoints, density-flow models, OOD split indices, supervised-probe outputs, and detector evaluation artifacts for the MOOD benchmark.
Anonymous review submission. Authors and affiliations will be filled in at camera-ready. The accompanying source code lives at https://anonymous.4open.science/r/MOOD-Bench-820B/ during the review period.
Layout
Per-setting directories are keyed by <dataset>/<arch>/<split>/fold_0/
(or seed_42/ under flow_models/), where <dataset> is one of the
five MatBench tasks, <arch> is one of alignn, cgcnn, schnet,
dimenet, and <split> is one of the 15 OOD predicates. Most
directories use the matbench_<dataset> form (matbench_dielectric,
matbench_log_gvrh, etc.); risk_coverage/ is the lone exception and
uses bare names (dielectric, log_gvrh, etc.).
| Path | Description | Approx. size |
|---|---|---|
embeddings/matbench_<dataset>/<arch>/<split>/fold_0/{train,id_test,ood_test}.npy |
Penultimate-layer GNN embeddings on ID train, ID test, and OOD test for every retained (dataset, architecture, split) setting. Released raw — not L2-normalized. Each fold_0/ also contains matching *_pred.npy and *_targets.npy for traceability. |
1.1 GB |
splits/matbench_<dataset>/<split>/{train_idx,id_test_idx,ood_test_idx,balanced_id_test_idx,balanced_ood_test_idx}.npy + stats.json |
MatBench-row indices for each split partition. The balanced_*_idx.npy files index the original MatBench dataset and are subsets of the corresponding *_test_idx.npy files; use them when evaluating on a 1:1 ID/OOD subsample. Also covers OMee data-driven split protocols (LOCO, SparseXcluster, SparseYcluster) under splits/omee/. |
7 MB |
checkpoints/matbench_<dataset>/<arch>/<split>/fold_0/{best_model.pt or *.keras, config.yaml} |
Trained GNN checkpoints. ALIGNN and CGCNN ship best_model.pt (PyTorch); SchNet and DimeNet++ ship *.keras (kgcnn). config.yaml documents the per-cell run (architecture, dataset, split_type, fold, embedding_dim, n_train / n_id_test / n_ood_test, best_val_mae). |
3.4 GB |
flow_models/matbench_<dataset>/<arch>/<split>/fold_0/seed_42/{flow_state.pt, id_log_prob.npy, ood_log_prob.npy, results.json, *_nll_history.npy} |
Trained Real-NVP normalising flows (8 coupling layers, hidden 128) plus pre-computed log-densities on ID and OOD test embeddings. | 4.1 GB |
linear_probes/matbench_<dataset>/<arch>/<split>/fold_0/results.json |
Per-setting linear-probe summary. Keys: mean_auroc, std_auroc, cv_aurocs (list of per-fold AUROCs from 5-fold stratified CV with C=1.0), n_id_used, n_ood_used, config. |
1 MB |
linear_probes_mlp/matbench_<dataset>/<arch>/<split>/fold_0/results.json |
Same per-setting summary for the MLP probe (hidden 256→128, alpha=1.0, early stopping). |
1 MB |
results/matbench_<dataset>/<arch>/<split>/fold_0/auroc.json |
Per-cell consolidated AUROC + FPR95 for every detector reported in the paper, plus a knn_sweep block over $k \in {5, 10, 20, 50} \times {\text{L2-norm}, \text{raw}}$. The metadata fields n_id_test and n_ood_test are the test-pool sizes used to compute these AUROCs. |
1 MB |
risk_coverage/<dataset>/<arch>/<split>/fold_0/<detector>/results.json |
Per-(cell, detector) risk–coverage curves for eight detectors with cluster-stored artifacts: flow, iforest, knn_k10, kpca, lof, mds_bic, norm, ocsvm. Keys: aurc_actual (the deployment-relevant AURC), aurc_oracle/aurc_random/aurc_constant (normalization references for SPE), spe, plus coverages and risks arrays for plotting. Note: this directory uses bare dataset names (dielectric/), not the matbench_dielectric/ prefix used elsewhere. |
10 MB |
croissant.json |
Croissant 1.0 metadata (Core + Responsible AI fields), enumerating every directory above. | — |
Benchmark axes
- 5 MatBench regression tasks: dielectric (refractive index), log_gvrh (log shear modulus), log_kvrh (log bulk modulus), perovskites (formation energy), phonons (highest phonon frequency).
- 4 GNN architectures: ALIGNN ($d{=}256$), CGCNN ($d{=}128$), SchNet ($d{=}64$), DimeNet++ ($d{=}64$).
- 15 deterministic OOD splits: 6 compositional (carbide, chalcogenide, halide, intermetallic, nitride, oxide) and 9 structural (cubic, hexagonal, tetragonal, orthorhombic, monoclinic, triclinic, high-spacegroup, low-spacegroup, perovskite).
The Cartesian product yields 300 candidate (dataset, architecture, split) settings; 257 are retained after filtering splits with fewer than 50 minority-class samples and excluding 7 settings where CGCNN training collapsed on phonons.
Representative sample for review
The full release is ~9.2 GB. For a smaller representative sample
(NeurIPS Evaluations & Datasets requires a sample for datasets > 4 GB),
the embeddings/matbench_dielectric/ subtree is a self-contained
slice:
- Size: ~132 MB (504
.npyfiles) - Coverage: 1 of 5 MatBench tasks (
dielectric) × all 4 architectures (ALIGNN, CGCNN, SchNet, DimeNet++) × all 14 retained OOD splits ×{train, id_test, ood_test}embeddings + matching*_pred.npy/*_targets.npy. - Sample URL:
/embeddings/matbench_dielectric - How the sample was created: the dielectric task was selected as
the smallest-by-disk method-bottlenecked dataset (132 MB embeddings)
while still covering the full benchmark structure — every architecture
and every retained split is represented, so a reviewer can drop in a
detector via the Quick start below and reproduce the layout the
benchmark exercises. The other 4 tasks (
log_gvrh,log_kvrh,perovskites,phonons) follow the identical layout in the full release.
Setup
pip install huggingface_hub numpy scikit-learn
huggingface_hub and numpy are required for the first two examples;
scikit-learn is needed only for the full reproduction example.
Quick start 1 — load embeddings for a new detector
import numpy as np
from huggingface_hub import hf_hub_download
REPO = "mood-anonymous/mood-benchmark"
SETTING = "matbench_dielectric/alignn/comp_halide/fold_0"
def fetch(name):
return np.load(hf_hub_download(
repo_id=REPO,
filename=f"embeddings/{SETTING}/{name}.npy",
repo_type="dataset",
))
z_train = fetch("train") # (n_train, d) raw
z_id_te = fetch("id_test") # (n_id_test, d) raw
z_ood_te = fetch("ood_test") # (n_ood_test, d) raw
# Distance- and KNN-based detectors should L2-normalize first; density-
# and isolation-based detectors typically use raw embeddings.
def l2(x): return x / np.linalg.norm(x, axis=1, keepdims=True)
Quick start 2 — read a per-cell risk–coverage curve
import json
from huggingface_hub import hf_hub_download
REPO = "mood-anonymous/mood-benchmark"
# risk_coverage/ uses bare dataset names (no "matbench_" prefix).
SETTING = "dielectric/alignn/comp_halide/fold_0"
with open(hf_hub_download(
REPO,
filename=f"risk_coverage/{SETTING}/mds_bic/results.json",
repo_type="dataset",
)) as f:
rc = json.load(f)
print("AURC (deployment):", rc["aurc_actual"])
print("SPE:", rc["spe"])
# rc["coverages"] / rc["risks"] are arrays for plotting risk vs coverage.
Quick start 3 — end-to-end detector evaluation (KNN k=20 norm)
A full evaluation loop for one detector: load embeddings, L2-normalize
for distance-based scoring, use the full ID and OOD test pools (sizes
match the n_id_test / n_ood_test metadata in auroc.json), and
compute AUROC.
import numpy as np
from huggingface_hub import hf_hub_download
from sklearn.neighbors import NearestNeighbors
from sklearn.metrics import roc_auc_score
REPO = "mood-anonymous/mood-benchmark"
SETTING = "matbench_dielectric/alignn/comp_halide/fold_0"
def load(p): return np.load(hf_hub_download(REPO, filename=p, repo_type="dataset"))
def l2(x): return x / np.linalg.norm(x, axis=1, keepdims=True)
# 1. Load embeddings.
z_train = load(f"embeddings/{SETTING}/train.npy")
z_id_te = load(f"embeddings/{SETTING}/id_test.npy")
z_ood_te = load(f"embeddings/{SETTING}/ood_test.npy")
# 2. L2-normalize (standard convention for distance-based detectors).
z_train, z_id_te, z_ood_te = map(l2, (z_train, z_id_te, z_ood_te))
# 3. KNN k=20 — mean Euclidean distance to k nearest train neighbours,
# sign-flipped so smaller distance scores higher (= more ID-like).
knn = NearestNeighbors(n_neighbors=20).fit(z_train)
score_id = -knn.kneighbors(z_id_te, return_distance=True)[0].mean(1)
score_ood = -knn.kneighbors(z_ood_te, return_distance=True)[0].mean(1)
# 4. AUROC (positive class = ID).
y = np.r_[np.ones(len(score_id)), np.zeros(len(score_ood))]
print(f"KNN k=20 norm AUROC: {roc_auc_score(y, np.r_[score_id, score_ood]):.4f}")
Per-cell AUROC and FPR95 for every reported detector are stored
alongside in results/<setting>/auroc.json for reference.
Optional — class-balanced 1:1 subsample
The full ID and OOD test pools are typically not the same size (e.g.
350 vs 1259 for the example above). For a strict 1:1 protocol, use the
balanced indices in splits/, which point into the original MatBench
rows rather than into the test-array positions:
SPLIT = "splits/matbench_dielectric/comp_halide"
id_test_idx = load(f"{SPLIT}/id_test_idx.npy")
ood_test_idx = load(f"{SPLIT}/ood_test_idx.npy")
bal_id_idx = load(f"{SPLIT}/balanced_id_test_idx.npy")
bal_ood_idx = load(f"{SPLIT}/balanced_ood_test_idx.npy")
# Map MatBench-row indices in balanced_*_idx → positions in the test arrays.
def positions(test_idx, balanced_idx):
pos = {int(i): k for k, i in enumerate(test_idx)}
return np.array([pos[int(i)] for i in balanced_idx])
z_id_b = z_id_te [positions(id_test_idx, bal_id_idx )]
z_ood_b = z_ood_te[positions(ood_test_idx, bal_ood_idx)]
# Now |z_id_b| == |z_ood_b| == min(|ID_test|, |OOD_test|).
Intended uses
- Evaluating new post-hoc OOD detectors on materials property
prediction GNNs without retraining the encoder (use
embeddings/). - Replicating the supervised-probe ceiling that drives the bottleneck
classification (use
linear_probes/andlinear_probes_mlp/). - Re-aggregating the headline AUROC matrix or computing alternative
metrics on top of per-cell raw scores (use
results/). - Replotting risk–coverage curves at any coverage threshold or
computing alternative selective-prediction metrics (use
risk_coverage/). - Re-running detectors that need the trained density model (use
flow_models/) or that need the full GNN forward pass on novel inputs (usecheckpoints/). - Studying the bottleneck dichotomy: dielectric and log_gvrh exhibit method bottlenecks (probe recovers signal, detectors do not); log_kvrh, perovskites, phonons exhibit encoder bottlenecks (no method recovers signal).
License
All released artifacts (embeddings, checkpoints, flow models, probe outputs, AUROC tables, risk–coverage curves): CC-BY-4.0.
Source MatBench data is not redistributed in this archive; it
remains under its original Materials Project licensing terms and is
obtained through the standard matminer loader.
Citation
@misc{mood2026,
title = {MOOD: Benchmarking Post-Hoc OOD Detection for Materials Property Prediction},
author = {Anonymous},
year = {2026},
note = {Under review},
howpublished = {\url{https://anonymous.4open.science/r/MOOD-Bench-820B/}}
}