Validation

AmorphGen has been benchmarked against a DFT-PBE0 reference for amorphous Ga₂O₃. The results below come from running the hybrid workflow (--hybrid-ensemble) — random placement followed by stages 4-7 (high-T anneal → quench → low-T eq → final relax) with CHGNet, NVT alongside Random and Full NPT melt-quench ensembles for comparison.

All ensembles are N = 20 structures. Plots and reports below come from the built-in analysis (amorphgen --analyse) so they exactly match what you would see if you re-ran this workflow yourself.

Note

Analysis cutoff convention. All coordination and bond-angle numbers on this page are produced with the default --cutoff auto-rdf, which finds the first minimum of each partial RDF and is the standard convention in neutron-diffraction analysis of glasses and liquids.

a-Ga₂O₃

System: Ga₁₆₀O₂₄₀ supercell (400 atoms), N=20 structures per ensemble

Reference: DFT-PBE0 ensemble from Kaewmeechai, Strand & Shluger, Phys. Rev. B 111, 035203 (2025)

Workflow: Four ensembles compared — DFT-PBE0 (PRB 2025), AmorphGen Random + CHGNet relax, AmorphGen Hybrid (Stages 4-7), AmorphGen Full MQ to 3000K (Stages 1-7, NPT).

a-Ga₂O₃ structure (Ga: dark, O: red)

Results vs DFT-PBE0 + experiment

Metric	DFT-PBE0	Random	Hybrid	Full MQ	Experiment
Density (g/cm³)	4.83	4.63	4.70	4.37	4.78–4.84
Ga–O bond (Å)	1.895	1.925	1.922	1.913	—
Ga–O coordination	4.42	4.38	4.42	4.33	~4.5 (EXAFS)
O–Ga–O angle (°)	107.5	107.7	107.6	107.9	—

Note

Local structure (bond, coordination, angles) matches the PBE0 reference across all three AmorphGen workflows. Density agreement varies: Random and Hybrid stay closer to PBE0 because their cells are constrained near the auto-estimated density; the Full MQ workflow (NPT) exposes preferred equilibrium density, which is ~9% lower than PBE0, This is noted as a limitation of MPtrj-trained MLIPs, that may not capture the liquid stuuctures.

Validation figure

Panels: (a) partial RDFs (Ga–O solid, Ga–Ga dashed, O–O dotted); (b) coordination distributions (Ga-centred top half, O-centred bottom); (c) bond-angle distributions (O–Ga–O solid, Ga–O–Ga dashed); (d) per-structure density compared with PBE0 reference and experimental range. Blue = DFT-PBE0 reference, orange = AmorphGen Random, green = AmorphGen Hybrid, pink = AmorphGen Full MQ.

Reproduce

# 1. Generate 20 random a-Ga2O3 structures
amorphgen --random-gen \
    --composition "Ga2O3*32" \
    --n-structures 20 \
    --work-dir random_ga2o3/

# 2. Run either Hybrid or Full MQ workflow

#   Option A — Hybrid (from random inputs, Stages 4-7)
amorphgen --hybrid-ensemble \
    --input-dir random_ga2o3/ \
    --config examples/hybrid_stages_4567_cuda.yaml \
    --work-dir hybrid_ga2o3/

#   Option B — Full melt-quench from a crystal supercell
amorphgen Ga2O3_supercell.xyz \
    --mq-ensemble --n-structures 20 \
    --config examples/mq_stages_1234_cuda.yaml \
    --work-dir mq_ga2o3/

# 3. Analyse against the bundled reference YAML
mkdir final && cp <workflow_dir>/run_*/run_0000/final_amorphous.xyz final/
amorphgen --analyse \
    --input-dir final/ \
    --reference examples/reference_a_Ga2O3.yaml \
    --save-report report.txt --save-plot plots/ --save-pdf

The reference file examples/reference_a_Ga2O3.yaml is shipped with AmorphGen and contains the PBE0 ensemble metrics plus experimental neutron/EXAFS data for automatic match/concern/fail scoring.

Data availability

A representative a-Ga₂O₃ structure ships with AmorphGen at examples/validation/ga2o3/example_final.xyz.

Reference data sources

• a-Ga₂O₃: Kaewmeechai, Strand & Shluger, Phys. Rev. B 111 (2025) 035203 (DFT-PBE0 ensemble); Stehlik et al., J. Non-Cryst. Solids 458 (2017) 14 (neutron + EXAFS); Yoshioka et al., J. Phys. Condens. Matter 19 (2007) 346211 (DFT-MD).