na-air-deepmd

Na₂O / Na₂O₂ / NaO₂ — Na-Air Battery Discharge Products (DeepMD)

What this is

A single DeepMD-kit potential covering Na-air battery discharge-product phases: Na₂O, Na₂O₂, NaO₂, and their mixed-phase interfaces (Na₂O–Na₂O₂, Na₂O₂–NaO₂, and the three-phase Na₂O–Na₂O₂–NaO₂ junction), trained across a shared composition space so the same model covers pure phases and their interfaces together (7 temperatures, 300–380K, per phase/interface).

Na-air (Na-O₂) batteries discharge by depositing one of these three sodium oxide phases at the cathode; which phase (and how it interconverts at phase boundaries) governs rechargeability and overpotential — hence training one potential across all of them together rather than phase-by-phase.

Transport properties

D (Na, AIMD) = 2.3×10⁻¹⁰ cm²/s, Eₐ = 0.21 eV · D (MLMD) = 2.5×10⁻¹⁰ cm²/s, Eₐ = 0.22 eV. Mechanical: E = 15 GPa, ν = 0.30, ρ = 2.2 g/cm³.

Files & Validation

RMSE values are validation-set (held-out) energy/force error, read directly from each run's DeepMD-kit lcurve.out at its final training step — not re-derived or estimated.

One or more files have no lcurve.out preserved on disk (training log not kept) — size/provenance is real, but no quantitative accuracy number can be reported for those.

Training pipeline

AIMD (VASP, PBE) across all phase/interface configurations → DeepMD-kit train/freeze/compress. Produced by HPCA (github.com/selvachandrasekaranselvaraj/hpca).

Citation

Selva Chandrasekaran Selvaraj, University of Illinois Chicago.