[Pw_forum] Fwd: relaxation of perovskite structure

[Lorenzo Paulatto]

Dear Bipul,

In data 06 agosto 2009 alle ore 11:27:43, Bipul Rakshit  
<bipulrr at gmail.com> ha scritto:
> 1. Do I have to simply run the vc-relax calculation and the results at  
> the end gives relaxed structure?

Yes

> 2. Do after relaxation the final Pressure P= , I got very low?

It depends on the threshold you've set. The default value is 0.5 Kbar

> 3. I have run the vc-relax calculation (still running). During  
> calculation I find that although pressure reaches comparitively lower  
> value ~ -2.01 kbar, but the (3x3) stress tensor matrix, the off diagonal  
> although zero, but the on-diagonal elements do show 11.52 Kbar pressure  
> also............

Because you've set press=10.0

> So my question is, why I am not getting total pressure P and all the
> on-diagonal element appreciable of some very low value?

Because you've asked the code to find a configuration where pressure is  
10.0 kbar, and that's what you will get!

> What more option I have to use in input file for my point 3?

I've noticed that you've set starting_magnetization=5.0 for two species,  
but the legal values are between -1 and 1

> Kindly guide me for the same.

kindly read the manual (INPUT_PW.html) that you can find in the Doc/  
directory!

regards


-- 
Lorenzo Paulatto
SISSA  &  DEMOCRITOS (Trieste)
phone: +39 040 3787 511
skype: paulatz
www:   http://people.sissa.it/~paulatto/

     *** save italian brains ***
  http://saveitalianbrains.wordpress.com/