[Pw_forum] Off diagonal elements of the dielectric function using turboEELS

[Gunnar Karl Pálsson]

Hi all,

I was wondering if turboEELS or some other aspect of TDDFT generalised to extended systems can calculate the off-diagonal elements of the dielectric tensor, for instance epsilon_xy? The reason I am interested in the off-diagonal components is for the calculation of the 
Magneto-Optical Kerr rotation angle which is proportional to this quantity. If it does not, is this a straight forward extension that could be done or is
there some inherent limitation? I see that it is possible to calculate these components with epsilon.x using the 'offdiag'
flag. For cubic systems the off-diagonal elements are probably zero but in the presence of spin-orbit coupling for a magnetic
material like bcc iron it could be possible to calculate given that turboEELS has nicely been extended to metals and 
can deal with spin-orbit coupling?

Best regards,

Dr. Gunnar Palsson
Researcher
Department of Physics and Astronomy
Uppsala University
Sweden