[Pw_forum] can someone help!

[Nicola Marzari]

xirainbow wrote:
> Dear George Manyali:
>
> 100 is the default value for scf iteration.
> You can change it by hand.

Also, if it has not converged in 100 iterations it might be that the 
system requires
different parameters to direct the scf cycles.

I would start by reducing the mixing parameter beta - try to repeat the 
calculation for
beta =0.7 0.6 0.5 0.4 0.3 0.2 0.15 0.1 0.08 0.06 0.04 0.02 and have a 
look at how the
total energy converges in all these different cases. With a small beta 
it will slow and
steady - as beta increases convergence will be faster, but for the 
largest beta you might
not converge at all.

Let us know what you find, as well !

             nicola

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