[Tingliangstu]

Summary

• Add virial_train.out metrics to the NEP training summary using eV/atom units.
• Use virial parity for panel (d) in nep_train.png when virial data exists.
• Keep the marginal nep_parity.png behavior unchanged: it still prefers stress when stress_train.out is present.

Validation

• python -m pytest tests\test_training_nep.py passed: 6 passed.
• Regenerated the real training plots from G:\co_project\Wangyixiu\train_NEP\1.initial_train.
• Verified real-data summary includes Virial 0.9741 0.0338 eV/atom 0.0590 eV/atom.
• Verified real-data panel routing: nep_train.png uses Energy, Force, Virial; nep_parity.png uses Energy, Force, Stress.

Note

A full local python -m pytest run is blocked in the current restricted sandbox because pytest cannot access C:\Users\liang\AppData\Local\Temp\pytest-of-liang, and this cmd environment is missing ase. GitHub Actions should validate in a clean environment.