spin-orbit matrix

[xiaoming_wang]

Hello,

I'd like to understand how to evaluate the SO matrix in vasp. Those parts of codes are in relativistic.F. Specifically, in subroutine SPINORB_STRENGTH it seems that the DLLMM variable already contains all the information of <phi_i|H_SO^alpha,beta|phi_j> where phi is the all electron partial wave, am I right? Then in the subroutine CALC_SPINORB_MATRIX_ELEMENTS the previous DLLMM is transferred as CSO which is to be multiplied by COCC, what's the meaning of COCC? Is it the augmentation occupancy? Why should the CSO be multiplied by COCC?

Best,
Xiaoming

[xiaoming_wang]

It seems that the SOC matrix elements reported at the end of OUTCAR are:

SOME(i,j)=Sum_n,alpha,beta f_n <\tilde_psi_n,beta|p_i> <phi_i|H_SO|phi_j> <p_j|\tilde_psi_n,alpha>

not exact the one given in the wiki wiki/index.php/LSORBIT, can the administrator please confirm this?

Best,
Xiaoming

[chengcheng_xiao1]

Same question here. Just wondering if Xiaoming found an answer?

[mmarsman]

Dear Xiaming,

You are right. The formula on the wiki is incorrect: the occupancy matrix is missing.
The matrix elements you are alluding to are indeed obtained by multiplication of the SOC strength with the one-center occupancies.
Thank you for pointing this out! We will make the necessary changes in our wiki.

Cheers,
Martijn Marsman