[Pw_forum] BFGS Relaxation

[Lorenzo Paulatto]

On Saturday, July 25, 2015 07:28:34 PM Kanak Datta wrote:
> 1. I just wanted to know whether the cutoff values are ok or not.......As I
> am from EEE background..I have very little knowledge on these things.....

They are problably not, you have to test convergence. You can use the initial 
geometry (if it is not completely off) with a single k-point. As you pseudos 
are norm-conserving you do not need to set ecutrho: the default value of 
4*ecutwfc is ok. On the other hand a convergen ecutwfc is going to be between 
40Ry and 120Ry, you'll see. As converged you can take 1mRy/atom, but if you 
want to study other properties you've better check convergence of those 
directly.

> 2. Besides should the van der waals corrections be applied in relaxation
> part from the beginning?

yes


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Dr. Lorenzo Paulatto
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