[Pw_forum] SCF convergency

[Eyvaz Isaev]

Hi, 

--- Jun-jun Yang <yang_jun-jun at hotmail.com> wrote:
>  But I noticed that the total energy is a 
> little higher than before (-5807 Ry
> vs. -5865 Ry). It seems that it's most likely a
> local minimum. 

Why you think about a local minima? 

> Should I  decrease the convergence
> threshold to 1e-7 or 1e-8? 

For test purpose, I assume, you can check lower
conv_thr, too.

> Probably, I need to start the calculation from 
> another point to avoid
> the local minimum. How can we do this in PWScf?
> 
Not so clear what what do you want. Please clarify.

> In my calculation, as you suggested, I set
> start_magnetization to 0.9 for 
> Fe, but I really don't
> know what number I should give for Cr. I just set
> 0.9 for Cr, 0.0 for O. Are 
> there any guideline
> to set these values?

starting_magnetization (and not start_magnetization)
is not a magnetic moment. It is (rho_up -
rho_dn)/(rho_up + rho_dn), obviously.  See 
"starting_magnetization" section in /Doc/INPUT_PW. For
O you can also specify non-zero
starting_magnetization.

Bests,
Eyvaz. 


	
		
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