[Pw_forum] piezoelectric constant

2012-08-12 Thread Stefano Baroni 
On Aug 11, 2012, at 7:47 AM, Alex Mariani wrote:

> 
> 
> 
> Dear all
> I want to calculate the piezoelectric constant for PbTio3.
> How do using the QE code?
> What is the procedure?

Simple solution: Perform a set of finite-field calculations and plot the stress 
as a function of the applied electric field. The slope at zero field gives you 
the piezoelectric coefficient(s).

A more elegant solution (which requires some coding, though) is described in: 
S. de Gironcoli et al. PRL 62, 2853 (1989), 
http://link.aps.org/doi/10.1103/PhysRevLett.62.2853

SB

---
Stefano Baroni - SISSA  &  DEMOCRITOS National Simulation Center - Trieste
http://stefano.baroni.me [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni 
(skype)

La morale est une logique de l'action comme la logique est une morale de la 
pens?e - Jean Piaget

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[Pw_forum] piezoelectric constant

2012-08-11 Thread GAO Zhe 
Dear Alex:
I think you can try Berry Phase implemented in the program pw.x.
Reference:
David Vanderbilt, Berry-phase theory of proper piezoelectric response, J. Phys. 
Chem. Solids, 61 (2000), 147


--
GAO Zhe
CMC Lab, Materials Science & Engineering Department,
Seoul National University, South Korea
 

At 2012-08-11 13:47:20,"Alex Mariani"  wrote:







Dear all
Iwantto calculatethepiezoelectric constant for PbTio3.
Howdo using the QE code?
What istheprocedure?
Pleasehelpme?


best regards
Alex Mariani


Magadh University

Department of Physics


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[Pw_forum] piezoelectric constant

2012-08-10 Thread Alex Mariani 





Dear all
I want to calculate the piezoelectric constant for PbTio3.
How do using the QE code?
What is the procedure?
Please help me?

best regards
Alex Mariani

Magadh University 

Department of Physics
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