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acell/xred in WFK file after relaxation run

Posted: Sun May 23, 2010 4:12 pm
by mverstra
Hello,

it appears that the WFK file written at the end of a relaxation run (ionmov 2 optcell 2) contains the _initial_ geometrical parameters (acell xred), before the relaxation, instead of the final values. This should be corrected, I think, as the wavefunction coefficients which are written pertain to the relaxed structure. This probably means there is no test on the final structure saved in the WFK file, e.g. using the cut3d analysis of the WFK after a relaxation.

However, for practical purposes, abinit will accept the WFK file anyway, and the calculation should be correct if the acell in the new input file is updated.

Any experience/comments?

Matthieu

Re: acell/xred in WFK file after relaxation run

Posted: Sun May 23, 2010 5:32 pm
by gmatteo
From the KNOW_PROBLEM file:

P51.22 (MGiantomassi060627)
The new value of rprimd is not stored in _WFK file .
So, restart cannot benefit from modifications of acell.
See his mail of June 27, 2006. See also P8.

Very old problem that has not been fixed yet!
Xavier told me that he tried to update the unit cell parameters
after the structural relaxation but some tests failed.
One should dig into the code as well as into the automatic tests to understand the reason!

Ciao

Re: acell/xred in WFK file after relaxation run

Posted: Sun May 23, 2010 7:32 pm
by gonze
Dear Matthieu and Matteo,

Interestingly, Guillermo pointed this problem to me a few days ago, because he has been
rewriting whole sections of the ionmov/=0 part of ABINIT. It is in the pile of things that
he will be looking at, during the next weeks (months ?)...

Best,
X.