[Pw_forum] QE & Xcrysden

[Lorenzo Paulatto]

On Wed, 10 Mar 2010 18:07:47 +0100, naphtaly moro  
<moronaphtaly84 at gmail.com> wrote:
> I am working on the various phases of GaAs. at normal conditions, GaAs
> assumes a Zincblende structures fcc ibrav=2, as pressure increases it
> assumes Rocksalt structure and then assumes a CsCl structure which is
> bcc ibrav=3 that is why my input as i posted it. Can you advice me
> further?


Dear Naphtaly,
according to what I see here:  
<http://cst-www.nrl.navy.mil/lattice/struk/b2.html> the CsCl structure is  
not BCC but simple-cubic. More specifically, the positions of Cs and Cl  
ions form together a BCC lattice; nevertheless, as Cl is not equal to Cs,  
you have to use a SC unit cell to describe the system.

regards

-- 
Lorenzo Paulatto

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