Dos Units

[Elizabeth_V]

I’m using the api to pull density of states, but it does not provide units. Does anyone know where I could find them?

[fraricci]

Hi Elizabeth,

the units for the DOS should be #states/eV.
You could verify this making a simple integral over the energies < efermi
and you should get the number of electrons in the system.
Something like this for Si:

dos = rester.get_dos_by_material_id('mp-149')
de=(dos.energies[-1]-dos.energies[0])/len(dos.energies)
ene_val = dos.energies<dos.efermi
np.trapz(dos.densities[Spin.up][ene_val],dx=de) ===> 7.93 

Note also that the values of the dos and energies are those directly from VASP DOSCAR file DOSCAR - Vaspwiki

Hope this helps,
Best

[jshen]

HI @Elizabeth_V there is an error with the units of the old DOS data generated using the non-scf uniform calcualtions from atomate1.

This problem is systemic and affects many DOS you can pull from the API. We haven’t figured out a scalining but the profile all look OK.

And rerunning a subset using different setting should give something like this

This problem goes back to data from a long time ago and hopefully everything will be fixed soon.
Best,
-Jimmy