[Wien] memory requirements (fwd)

[Peter Blaha]

NMATMAX and NUME=100000 is really great!
A matrix of 100000 would require a memory of about 100 GB (or 200 for
complex) memory ! And it would run quite some time (~1000 h for one
k-point)

NUME should typically be 10-20 % of NMATMAX

I suggest you use the default values which come with WIEN2k or at least
read the explanations given in siteconfig, when you should set NMATMAX.
The defaults are fine for beginners and when you really come to
larger systems (WARNINGS in the scf file) you can redimension.

>     Tru64 - DEC Alpha - 4 CPU - 4G Memory
>       PARAMETER          (NMATMAX=   10000)                  ok
>       PARAMETER          (NUME=   10000)               too large. ~1000
>
>     IRIX - Origin 3800 - 32 CPU - 32G Memory
>       PARAMETER          (NMATMAX=   100000)     use the same as above
>       PARAMETER          (NUME=   100000)
>

> >>I'm running a 16 atom cell in two different

For 16 atoms/cell the defaults are more than enough


                                      P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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