[Wien] supercell does not converge

[E B Lombardi]

1. For surface supercells which have a number of bands close to the 
fermi level, TEMP smearing (see .in2) can help speed convergence. Also 
make sure you have a sufficiently large RKMAX and number of k-points.
2. For difficult to converge cases, the mixing factors in .inm can be 
changed - see section 7.9 in the Users Guide. Also search for 'Mixer' in 
the Wien2k mailing list.

See also:
http://zeus.theochem.tuwien.ac.at/pipermail/wien/2006-November/008367.html
http://zeus.theochem.tuwien.ac.at/pipermail/wien/2005-May/005253.html

Regards
Enrico


Chandrika wrote:
> Hello Wien users,
> A supercell of Al (2x2x2) with vacuum slab (4 Ang) does not converge 
> (GGA No 13). Input parameters are FCC (SG 225), RMT= 2.25, kmax = 3.1, 
> k points = 2 and 10, convergence criteria= default.
> The unit cell itself converges. The problem is only with the supercell.
> What parameters should be varied to make the scf converge?
> Your help will be appreciated.
> Thank you,
> Chandrika
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-- 
Dr E B Lombardi
Physics Department
University of South Africa
P.O. Box 392
UNISA 0003
Pretoria
South Africa

Tel: +27 (0)12 429 8654 / 8027
Fax: +27 (0)12 429 3643
E-mail: lombaeb at science.unisa.ac.za