[Wien] NUME parameter

Peter Blaha pblaha at zeus.theochem.tuwien.ac.at
Wed Nov 19 16:33:44 CET 2003


> Is the size of NUME at all hardware related, or should one increase this
> value from the default for machines with larger memory. Am about to
> compile on a 2 Gb machine. Was going to use the following parameters
>
> NMATMAX 20000 real ... 10000 complex

?? 2 x 2 = 4  .... needs about 4 Gb of memory!

> NUME ???? real ... ???? complex

Besides the matrices NMATxNMAT there is a big array of "eigenvectors" of
dimension NUME*NMAT

If you assume: NMAT=10000 ==> 100 atoms/cell; 1 atom -->about 10 states (s,p,d)
==> you will have at most 1000 eigenvalues to consider.
(Of course when semicore states or f-states or many unoccupied states are
of interest you may increase it. Also, maybe you want to handle 200 atoms
with NMATMAX=10000, so double it,.....

Typically set NUME about 10-20% of NMATMAX.

                                      P.Blaha
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