training with only energy data

[wuziqi-cmu]

Hi there, I can see in minimal_eng.yaml, under the loss function, it only has energy. However, if I provide a dataset with no force data, I still get a runtime error saying that The field key forces is not present in this dataset. Why do we still need force data if the loss function only has energy in it? and Is it possible to train a model with only energy data?

[Linux-cpp-lisp]

Hi @wuziqi-cmu ,

Can you provide a complete error backtrace?

[wuziqi-cmu]

Traceback (most recent call last):
  File "/usr/local/bin/nequip-train", line 8, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.10/dist-packages/nequip/scripts/train.py", line 72, in main
    trainer = fresh_start(config)
  File "/usr/local/lib/python3.10/dist-packages/nequip/scripts/train.py", line 163, in fresh_start
    final_model = model_from_config(
  File "/usr/local/lib/python3.10/dist-packages/nequip/model/_build.py", line 96, in model_from_config
    model = builder(**params)
  File "/usr/local/lib/python3.10/dist-packages/nequip/model/_scaling.py", line 20, in RescaleEnergyEtc
    return GlobalRescale(
  File "/usr/local/lib/python3.10/dist-packages/nequip/model/_scaling.py", line 82, in GlobalRescale
    computed_stats = _compute_stats(
  File "/usr/local/lib/python3.10/dist-packages/nequip/model/_scaling.py", line 330, in _compute_stats
    values = dataset.statistics(
  File "/usr/local/lib/python3.10/dist-packages/nequip/data/dataset.py", line 450, in statistics
    raise RuntimeError(
RuntimeError: The field key `forces` is not present in this dataset

Hope this helps. Also attached the dataset and yaml file below. Let me know if you need something else.
bcc.zip