Unable to load 'default_magmoms.yaml'

Hello All,

I am testing several workflows and have noticed for each workflow submission I receive the warning,

UserWarning: Could not load default_magmoms.yaml, falling back to VASPIncarBase.yaml
warnings.warn("Could not load default_magmoms.yaml, "

And as a result the INCAR for each respective run sets the MAGMOM tag to zero. I believe this may be impacting the accuracy of my calculations. Please advise on how to correct this.


Hi Dennis,

Try updating your pymatgen? (pip install pymatgen --upgrade) There was a bug with an older version where the file wasn’t included, but it should now be installed when pymatgen is installed. You can also put the file into the relevant pymatgen folder (pymatgen/analysis/magnetism) manually: https://github.com/materialsproject/pymatgen/blob/d94e76c1dd903472451cba886927fcaeb963ae25/pymatgen/analysis/magnetism/default_magmoms.yaml

Also note that the magnetic workflow has a keyword argument (default_magmoms ) to supply your own magmoms dictionary, so you can do that too, e.g. default_magmoms={"Fe": 5}. If you supply the magmoms yourself in this manner, you do not need the default_magmoms.yaml file.

Hope this helps, let me know if there are other questions!


Manually creating the ‘default_magmoms.yaml’ file worked. Thanks!