Question about nequip training and evaluation

[baham2]

Hello,

Thank you for developing and maintaining this package.

I have trained a Nequip model on my periodic system using the attached config.yaml file. My dataset includes trajectories from two different temperatures of the same system. After training, I achieved a validation MAE of 0.0004 eV/atom for energy and a force MAE of 0.02 eV/Å, along with smooth learning curves. Following the training, I used the same config file to evaluate the model on the training and validation datasets (nequip-evaluate --model train_dir/best_model.pth --dataset-config config.yaml --batch-size 1 --output ./output.xyz). However, I have two questions:

1. Although I have the pbc key in my dataset (shape: nframes*3, type: boolean), the pbc is printed as F (pbc="F F F") in the output file. I am wondering if this is a typo or if the pbc is in fact turned off during evaluation (or possibly during training as well)?
2. I have plotted the energy error distribution for each temperature (attached). It appears that the Nequip predictions have a positive offset for the lower temperature and a negative offset for the higher temperature. Is this behavior expected, or could something be going wrong?

Thank you for your help.
config.txt