[Wien] LDA+U changed between the versions?

[Laurence Marks]

Two comments:

1. There was a bug in the density matrix mixing which was introduced
with the hybrids (around Wien2k 8.X) which is corrected in 10.1. You
may want to use the file read_denmat.f and write_denmat.f from the
current SRC_mixer and replace the 9.2 versions, use the current
SRC_mixer instead of your 9.2 version or (probably best) update to
10.1. If you do not update keep a copy of the old versions just in
case!

2. Even though you think a LDA+U, hybrid or similar calculation is
converged in terms of -cc or -ec, it may not in fact be properly
converged. In the 10.1 version you want to do a grep -e :DMATR to
check, look (by hand) at the new/old density matrix files. You can
also do a grep -e :MVORD for 10.1 and some earlier versions. The 10.2
mixer should do a better job.

On Mon, Aug 2, 2010 at 4:16 PM, mazin <mazin at nrl.navy.mil> wrote:
> This may have been already discussed here, but here is the question:
> I have a calculation (CeTe3, if that matters) that was 2 years ago converged
> with LDA+U (FLL, U=0.32 Ry, J-0) and spin-orbit.
>
> Now if I try to run WIEN2k_09 on these files, it finds the calculation
> completely unconverged and eventually converges to a different solution,
> with the lower Hubbard band 1 eV higher and affecting the Fermi surface (the
> UHB is also higher by 1 eV). If I run my old WIEN2k_07 executable instead, I
> get the same result as before. In fact, my old calculation then appears
> fully converged when I run the '07 executable.
>
> Has something drastically changed in the way how LDA+U is implemented or in
> the way how it interacts with spin-orbit?
>
> Thanks!
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>



-- 
Laurence Marks
Department of Materials Science and Engineering
MSE Rm 2036 Cook Hall
2220 N Campus Drive
Northwestern University
Evanston, IL 60208, USA
Tel: (847) 491-3996 Fax: (847) 491-7820
email: L-marks at northwestern dot edu
Web: www.numis.northwestern.edu
Chair, Commission on Electron Crystallography of IUCR
www.numis.northwestern.edu/
Electron crystallography is the branch of science that uses electron
scattering and imaging to study the structure of matter.