[gpaw-users] Local Green's functions from GPAW for MND calculation?

[Thomas Olsen]

Hi Toma

What do the indices here refer to? I am guessing that (nk) are Kohn-Sham state indices and (lms) are angular momentum indices for a given atom. In that case it is trivial since <lms|nk> are well approximated by the projector overlaps, which are computed in any standard GPAW calculation. You can also calculate the all-electron overlaps if you like, but that is a bit more involved. I can give you a quick example of how to get them if you like. Or you can have a look at the PDOS page in the GPAW documentation.

/Thomas

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Fra: gpaw-users-bounces at listserv.fysik.dtu.dk [gpaw-users-bounces at listserv.fysik.dtu.dk] på vegne af Toma Susi [toma.susi at univie.ac.at]
Sendt: 25. februar 2015 14:56
Til: gpaw-users
Cc: Jan Rusz
Emne: [gpaw-users] Local Green's functions from GPAW for MND calculation?

Greetings,

I had the pleasure of meeting Jan Rusz from Uppsala recently, and heard of a nice implementation of the dynamical core-hole screening of Mahan, Nozieres and De Dominicis that he has been using. The calculations make use of initial and final state local Green’s functions:

G_lms,l'm's'(E) = \sum_kn <lms|kn><kn|l'm's'> / (E_k - E - i*eps)

To my understanding of these things, it does sound this is designed with plane-wave codes in mind. Jan has written a small code for WIEN2k for calculating these, and there exists a MATLAB script from VASP outputs. The real computational task is apparently getting the converged final state for each atom of interest.

Since I know GPAW is rather nice for final state calculations, I was wondering if it would be possible to get the right kind of output from GPAW? Jan thinks we need the code to be able to provide <kn|lms> projections from the Bloch states, but perhaps something equivalent would be available in GPAW? However, I wouldn’t want to use the PW mode, since the main interest would be to calculate rather extended defects.

Either a quick “no, cannot be done” or a “yes, trivial to implement, let me help” answer would be ideal! :-)

Many thanks,
Toma

________________________________
Dr. Toma Susi
FWF Lise Meitner fellow
University of Vienna, Austria

http://mostlyphysics.wordpress.com

"Love is the only emotion that enhances our intelligence."
-Humberto Maturana

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