[Wien] optimization

[Stefaan Cottenier]

> If i send the structure file, could someone tell me the optimal values of
>
> RMT

Follow the guidelines at the wien2k FAQ (www.wien2k.at)

> Kmax

The default RKmax=7 is very often good. Test yourself in a range starting
from 5.0 and going to as high as you need to obtain stable observable
quantities (9.0 at most). Take a step of 0.5 (5.0 - 5.5 - 6.0 - ...)

> G max

The default of 14 is almost always OK (if you don't have Hydrogen in your
cell).

> Mixer

This influences only the number of iterations you will need, not the
accuracy. 0.05 - 0.15 for magnetic calculations, 0.20 - 0.40 for nonmagnetic
ones (use smaller values for very large unit cells, > 20 atoms, or for cases
that are 'delicate' in any respect).

> k points (IBZ).

Again something to test yourself. Take a moderate RKmax (6), take the lowest
k-mesh you can have (1 pt in IBZ), converge (if possible), roughly double
the k-mesh, and continue, until observable quantities are converged.

Stefaan