[Pw_forum] elastic properties

[Eyvaz Isaev]

Dear Kada,

>From: kada galami <physolde at yahoo.fr>

 
> 1- we do the calculation of elastic propreties only with ibrav= 0

Not necessarily, it may depend on system considered and a strain applied. 
As example, for  an orthorhombic  strain (for B2 structure)  you can use ibrav 
by default.

>2-  i read about the input ibrav= 0 
>we have to put only the celldm(1)

Correct.

> and the cell parameters
> where i can get the cell parameter, i think have somthing with basic vectors

Take your basis vectors for undistorted  lattice and multiply by the strain 
matrix.
Do not forget to transform your atomic positions in the same manner.

Thanks Stegano G.  for the explanation how to apply CELL_PARAMETRS with ibrav=0.

Bests,
Eyvaz.

  
 -------------------------------------------------------------------
Prof. Eyvaz Isaev, 
Department of Physics, Chemistry, and Biology (IFM), Linkoping University, 
Sweden 

Theoretical Physics Department, Moscow State Institute of Steel & Alloys, 
Russia, 

isaev at ifm.liu.se, eyvaz_isaev at yahoo.com



      
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20101227/10ccb376/attachment.html>