[Wien] Estimating the memory needed by a job

[Peter Blaha]

> How can I estimate the resources a wien-job will need?
>
> Eg., Siteconfig tells us about 1 Gb of memory is needed to use
> nmatmax=10000.  This seems logical : a double precision real matrix of
> dimension N consists of 8*N*N = 8 10^8 bytes (and twice as much for a
> complex matrix, obviously).
>
> But how about other parameters, eg., NUME?
> When I compile with increased nume (eg 2500 instead of 2000 in my case)
> I am not able to run lapw1 anymore; I get crashes like
>
> Allocate error 494: Allocation of Array with extent of 28065960 failed
> End of diagnostics

There is an additional array for the eigenvectors Z(NMATMAX,NUME)
which, depending on the ratio of NUME / NMATMAX , may add some significant
fraction to the memory if NUME is large compared to NMATMAX.

                                      P.Blaha
--------------------------------------------------------------------------
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/
--------------------------------------------------------------------------