[WIEN] How to speed up slab calculation!

[Lukasz Plucinski]

Hello All,

I am running ZnSe(001) slab of 13 atoms (7 Zn and 6 Se) for 4 days now.
Convergence seems to be fine, but its a long time to wait. It would be
even much longer when I want to relax the surface (minimize forces).

I must admit that using a pseudopotential code the calculation was much
faster, however, the disadvantage was that Zn 3d were not included (on
the other hand their position is always wrong when using DFT-LDA or GGA).
It was in fact like 1-3 days to calculate 60-atoms slab separated with
vaccum equivalent to the thickenss of the slab.

I am pretty sure there are ways to speed up WIEN calculation by making
it less accurate - I would like to ask for some advise which parameters
could be changed to make it faster?

Maybe my problem is also hardware since I am using serial code with
Linux on PIII 1Ghz, 2 GB RAM. But I was using the same machines with
pseudopotential code.

I used pgf90 to compile WIEN.

Regards from Boston,

Lukasz