Perform non-relativistic ground state calculations

Hello,
I assume that the default setting involves relativistic-KS Hamiltonian. Is there a way to switch it OFF and only perform a non-relativistic calculations. (For example, "exciting" dft has a couple of flags to switch off the coreRelativity and valenceRelativity). Is there an equivalent in Elk. I tried searching in the manual but couldnt find any such flag.
Thanks,
Nelson

J. K. Dewhurst - 2019-10-28

Hi Nelson,

You can scale the speed of light using (for example)

solscf 100.0

This scales the speed of light everywhere in the code by 100.0 and affects both core and valence states. In effect, this would make the calculation non-relativistic.

You can also enable spin-orbit coupling for the valence states with

spinorb .true.

and then scale this term in the Hamiltonian with (for example)

socscf 0.1

Both solscf and socscf are continuous variables so you can plot various quantities as a function of these in order to understand the effect of relativity.

Regards,
Kay.