[Pw_forum] error in optic properties

[Lorenzo Paulatto]

On 07/30/2014 11:02 AM, ashkan shekaari wrote:
> dear fataneh
>
> you are out of RAM .
>
> for this reason :
>
> 1- kinetic-energy cutoff (ecutwfc) is of large value , i suggest 60 0r 70 Ry
>
> 2- charge density cutoff (ecutrho) is of large value , i suggest 170 or 200 Ry
>
I'm curious where did you get these numbers from?

Using less than 4 times the cutoff of kinetic energy for charge density 
is not something that should be done without careful testing.

kind regards


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Dr. Lorenzo Paulatto
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