Convert EOS output units to eV-Ang³

[Ouettar Chaouki]

I want to use Elk's eos files to do enegry-volume fitting but I want the results to be in angstron³ and electron-volt. Which files to modify? and how to modify them to do that?

[Miroslav Iliaš]

Hello,

please is there some tool for converting crystal geometries (in cif or xyz formats) into elk.in template ?

Miro

[mfechner]

Hi,

there is a nice toolbox for doing this

see

https://pypi.org/project/cif2cell/

which also supports elk

best wishes
Michael

[mfechner]

I think its easier to convert the final result, rather than to rewrite the code

[Ouettar Chaouki]

Yes that's right, but I want to obtain the fitted E vs V cuves in those units.

[Andrew Shyichuk]

Elk output is in Hartree (energy) and Bohr (length).
1 Ha = 27.21138624599 eV
1 Bohr = 0.529177210904 Angstrom
1 Bohr^3 = 0.148184711473 Angstrom^3
In EOS plot, multiply Y by 27.21138624599 and X by 0.148184711473, and you got it.

[J. K. Dewhurst]

The National Institute of Standards and Technology (NIST) Reference of Constants, Units and Uncertainty is an excellent resource for converting units and looking up physical constants.