[CPMD-list] STRESS TENSOR

[Axel Kohlmeyer]

On Mon, 18 Oct 2004, Jiri Houska wrote:

JH> Hi,

hi,

your observation is correct. the conventions for the stress in cpmd
are different from what you'd normally expect. you can easily
check that by performing a few single point calculations e.g. 
with bulk silicon (64 atoms, gamma point and 50ry cutoff should be 
sufficient and rather fast) where you use fractional coordinates 
and change the lattice constant.

best regards,
	axel kohlmeyer.

JH> I calculated some stresses in amorphous materials simulated by cpmd
JH> (keyword STRESS TENSOR, section &CPMD, results in KBar). However, the
JH> results are a bit strange (before & after Pulay correction), may be
JH> due to the wrong +/- sign. Can anybody confirm that for the program,
JH> the compressive stress is negative and the tensile positive (as usual
JH> in physics)? Thanks a lot.

JH> Jiri Houska
JH> School of Physics
JH> University of Sydney
JH> 
JH> 
JH> 
JH> _______________________________________________
JH> CPMD-list mailing list
JH> CPMD-list at cpmd.org
JH> http://cpmd.org/mailman/listinfo/cpmd-list
JH> 
JH> 

-- 


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Dr. Axel Kohlmeyer                        e-mail: axel.kohlmeyer at rub.de
Lehrstuhl fuer Theoretische Chemie          Phone: ++49 (0)234/32-26673
Ruhr-Universitaet Bochum - NC 03/53         Fax:   ++49 (0)234/32-14045
D-44780 Bochum  http://www.theochem.ruhr-uni-bochum.de/~axel.kohlmeyer/
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