[Wien] mixing vs. lapw2 CPU time

[Stefaan Cottenier]

> > Using the "-ec 0.0001 -cc 0.0001 -fc 0.5" options is a bit of paranoia
on my
> > part. I don't quite trust the results unless I see that everything has
> > converged.

> I don't think this works. Only the LAST criterium will be checked, since
> we have in the run_lapw script:

I'm 'suffering' from this kind of paranoia as well (and I hope many of us do
;-) ). This is how I usually proceed:

A) For cases where I'm interested in just a single property, I pay attention
to the convergence of that property only, and only to the precision that is
needed. Two frequent examples are the total energy (for instance for a
energy-versus-volume curve, eg. -ec 0.0001) and forces (for a relaxation,
eg. -fc 1.0).

B) For a case where several and maybe sensitive properties need to be
studied, or when I want to have it really accurate for other reasons, I
always converge with -cc : if the density is converged, then everything is
converged. Most often I take a crazy small value (-cc 0.000001) that almost
never will be reached, and then put a .stop file when manual inspection of
case.scf shows that all physical properties (:ENE, :MMI, :HFF, :EFG, :ETA,
:RTO, :FOR, ...) have converged.

Stefaan