[CP2K-user] [CP2K:22419] Underestimation of SOC splittings

[Nisarg Trivedi]

Dear CP2K community,
I have been trying to benchmark/test the spin orbit coupling capabilities 
in CP2K, by measuring the spin orbit splitting of the valence bands of 
Silicon at the gamma point. 
These calculations were performed on CP2K v2025.1 using the 
GTH_SOC_POTENTIALS and TZV2P MOLOPT basis.

The values I get are much smaller than the reported theoretical literature 
and experimental values. From this run, CP2K gives 22 meV of splitting. I 
have attached the input file (si.inp) and the output bandstructure file 
(bandstructure_si). 
The same structure ran through QE with fully relativistic pseudopotentials 
gives 48 meV of splitting; which is closer to the experimental value of ~43 
meV. 

It would really be helpful if someone can clear it up if I have made a 
mistake in the input/calculation or this is a known limitation of the 
pseudopotential/method used in CP2K?

Best regards,
Nisarg.

-- 
You received this message because you are subscribed to the Google Groups "cp2k" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cp2k+unsubscribe at googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/cp2k/45561b15-4253-4176-b982-1f8d105a3e6en%40googlegroups.com.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20260904/982577e3/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: bandstructure_si
Type: application/octet-stream
Size: 65289 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20260904/982577e3/attachment-0001.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: si.inp
Type: chemical/x-gamess-input
Size: 1292 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20260904/982577e3/attachment-0001.inp>