[Pw_forum] vc-relax bug?

[Javier Antonio Montoya]

Hello dear all,

In recent days I have been trying to get a triclinic cell to have a diagonal
stress by using vc-relax. The pw.x program reads data in the correct way,
calculates the right starting volume for the cell given as input and also
seems to do right the first electronic minimization but, as soon as the
Wentzcovitch Damped Cell-Dynamics Minimization starts, it gives cell
parameters and ion positions that are not consistent with the energies and
stress that it prints (i.e. if you take those cells and ions to an
independent scf run the final energy and stress differ from the ones in the
vc-output) the problem is that in the end, when I get a nice diagonal stress
after 60 or more dynamic steps, the difference between the reported energy
in the vc-output and the energy of the system that you get with the cell and
ion parameters shown is of almost 1 Ry and the pressures differ by more than
10GPa. Any idea? by the way the ph.x complain and doesn't get anything from
such restart files.
The output files are huge for sending by e-mail because my system is 72
atoms big, but I can provide them.

cheers,

JAvier.
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