No subject

case.struct and case.inM present? min_lapw is a kind of shell around a normal 
scf-calculation, that does a task like this:

calculate forces (in a normal scf-cycle = run_lapw)
move positions of atoms
calculate forces (in a normal scf-cycle = run_lapw)
move positions of atoms
calculate forces (in a normal scf-cycle = run_lapw)
move positions of atoms
calculate forces (in a normal scf-cycle = run_lapw)
move positions of atoms
calculate forces (in a normal scf-cycle = run_lapw)
etc.

This stops when the forces are close to zero. Therefore, you obviously must do 
a normal initialization first. The only additional file that is needed is 
case.inM (see the FAQ ('minimization of forces') about how to choose the 
parameters in case.inM).

> I hope it IS in general possible to relax big slab using min_lapw...

Sure, but it might take quite some time :-(  

Stefaan