Add mag_density to VASP output doc

[Andrew-S-Rosen]

This PR adds a mag_density attribute to the VASP CalculationOutput document. This can sometimes be more useful to query by than total_mag because the former is invariant to the # of unit cells.

[codecov-commenter]

Codecov Report

Merging #65 (4cc7448) into main (fe5d8a6) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main      #65   +/-   ##
=======================================
  Coverage   70.39%   70.40%           
=======================================
  Files          45       45           
  Lines        3804     3811    +7     
  Branches      576      576           
=======================================
+ Hits         2678     2683    +5     
- Misses        979      981    +2     
  Partials      147      147           

Impacted Files	Coverage Δ
src/atomate2/vasp/schemas/calculation.py	83.85% <100.00%> (+0.12%)	⬆️
src/atomate2/utils/path.py	88.23% <0.00%> (-11.77%)	⬇️
src/atomate2/vasp/flows/core.py	93.91% <0.00%> (+0.27%)	⬆️

[Andrew-S-Rosen]

I just need to point the test to atomate2/tests/test_data/vasp/magnetic_run/ so that I can read the proper vasprun.xml.gz and OUTCAR.gz. I'm not sure the ideal way to do that given the current way Atomate2 is set up.

[utf]

You can just do:

def my_test(vasp_test_dir):
    dir_name = vasp_test_dir / "magnetic_run"

As vasp_test_dir is a pytest fixture which defines the root directory of the vasp test data.

[Andrew-S-Rosen]

Thanks! That was easy!

[utf]

Is this still a WIP?

[Andrew-S-Rosen]

Thanks for asking! Nope. My bad!

[utf]

Great thanks very much!