Selectively turning on spin-orbit coupling for particular atoms?

[srdjan_stavric1]

Dear members of the VASP community,

I have a question regarding spin-orbit coupling (SOC). In VASP, when it is turned on with LSORBIT=.TRUE. flag, it is turned on for all the atoms in the structure.
I am curious is there a way to turn on SOC only for some particular atoms / atomic species, or to artificially tune the strength of SOC by changing "Lambda"
from 0 to 1?

Thank you for your suggestions,
Dr. Srdjan Stavric (CNR-SPIN, Chieti, Italy)

[martin.schlipf]

There is no such feature that is available through the standard input files. To achieve what you want to do you would need to hack the code and recompile. You can e.g. change the SOC strength by modifying the speed of light. Please look at the code in relativistic.F but proceed with caution. Unfortunately, we cannot provide support for implementing these changes, so come up with some reasonable test cases and monitor the Spin-Orbit-Coupling matrix elements reported to the OUTCAR file.

[srdjan_stavric1]

Thanks a lot Martin, maybe changing the speed of light will do the trick for me.

Srdjan