[Wien] What is p-1/2 LOs ?

[Stefaan Cottenier]

>     I am doing a calculation with spin orbit coupling. I need to define 
> the case.inso files, but I
> dont know how to add the p-1/2 LOs,ie. the El to increase accuracy as 
> the instruction said.I
> use the El in case.in1 files, but the result is poor convergence.I want 
> to know what is the p-1/2
> LOs and how to define them.I appreciate your help.

In a relativistic treatment, p-electrons are indexed not by l=1 and 
their spin s, but by the quantum number j, which is either l-s=1/2 or 
l+s=3/2. In a density of states, you see this as a split of the p-peaks 
in two parts. This splitting is reproduced by LDA+spin-orbit poorly, 
unless you go to very high Emax (>10). In order to get the correct 
splitting using smaller Emax (3), you can 'help' the basis set a bit by 
adding LO's that have the proper shape for these p-1/2 orbitals.

This is useful only for heavy atoms (5p, 6p). If this is not your case, 
then do not add p-1/2 LO's.

Stefaan