[Q-e-developers] Fwd: [Pw_forum] mistake in impose_deviatoric_strain_2d

[Paolo Giannozzi]

If nobody comments, I'll assume he is right and commit. Paolo

---------- Forwarded message ----------
From: Niels Walet <niels.walet at manchester.ac.uk>
Date: Fri, Aug 14, 2015 at 2:09 PM
Subject: [Pw_forum] mistake in impose_deviatoric_strain_2d
To: "pw_forum at pwscf.org" <pw_forum at pwscf.org>


Hope this helps someone:
in pw.x (espresso 5.1.2), with
                  cell_dofree = '2Dshape' ,
the area (and volume) of the cell are actually not conserved.

Digging around a bit, it looks like the power is wrong in flib
impose_deviatoric_strain_2d:
In line 59, the power of 1/3 should be 1/2 (i.e., the final 3.d0 should be
2.d0), otherwise area is not conserved!!!
Niels

---
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-- 
Paolo Giannozzi, Dept. Chemistry&Physics&Environment,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
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