[Pw_forum] choosing ecutwfc through vc-rx

[Mehrnaz Anvari]

Dear all
I have some fundamental questions.
1.If  I  want to achieve the equilibirium value of lattice paramrters (such 
as a, c,...) is it possible to replace bulk modulues calculations with 
vc-rx?
2.when I use vc-rx for my material most of the time after 300 stpes the 
stress becomes approximately zero(-0.6-0.6) but energy doesn't converge. I 
don't pay attention just use the cell parameters & atomic positions to do 
scf calculations. I tried to achieve convergency in scf calculation with 
changing ecutwf & k-points. Now I think it couldn't be true & I have to 
optimize my ecutwfc during vc-rx calculation (Is it true?) what about 
k-point ,where could I optimize it?
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