[Pw_forum] Equation of state with PW.x

[David Furman]

Hello dear users and developers,

 

I'm trying to calculate the equation of state of Europium oxide, but I have
some doubts regarding my procedure.

I have the xyz coordinates of the unit cell in angstroms which I put into
atom_positions and also define the needed celldm's().

 

I'm interested to compress the material to different values (say, 0%, 10%
and 20% volumetric compression) and calculate the total energy each time.

 

Do I have to change the given initial xyz coordinates in atom_positions AND
the celldm() , or just change the celldm() accordingly to the compression
and pw.x will do the proper changes to the positions of the atoms ?

 

I have done some calculations with uncompressed unit cell and with 20%
compressed unit cell (by changing to the proper compressed celldm() values)
but the difference in energy was about 0.5 Ry which i believe to be quite
small. (Of course I checked previously for convergence).

 

Am I doing it wrong ?

 

Any help will be greatly appreciated 

 

David Furman, Graduate Student | Fritz Haber Research Center for 

Molecular Dynamics, The Hebrew University of Jerusalem | +972-8656-8909

 

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