SOC with local 6p1/2 orbitals

Dear all,

i have read in the book "Plane waves, pseudopotentials and the LAPW method" that calculations of the actinides with SOC suffer from a bad description of the 6p1/2 orbitals and that local 6p1/2 orbitals should be added in the second-variational step to cirumvent this problem. Is this approach integrated in the Elk code or is there otherwise another possibility to tackle this problem?
Best regards,
Malte Sachs

Lars Nordström - 2019-05-21

Dear Malte,
it is not implemented, but the worst effect comes when you e.g. optimise volume with varying muffin-tin radius. So by keeping this radius constant the effect is almost gone. However, if you are interested in e.g. the spin-orbit splitting of the 6p state you are in trouble, if you cannot keep it in the core ...
Best wishes,
Lars

Last edit: Lars Nordström 2019-05-21

Malte Sachs - 2019-05-22

Dear Lars,
thank you for your quick response. As I am interested in magnetic properties I think I can safely ignore that issue then...
Best regards,
Malte

Dear Malte, dear Lars,
I remember that I've had some trouble with that when I was looking at topological insulators that included Bi. I think the band structures looked quite a bit different from Wien2k band structures, where the 6p1/2 LO was included. There is no solution for this in elk.
Best wishes,
Markus

https://sourceforge.net/p/elk/discussion/897820/thread/5b1a693199/