Reuse DENx in an interrupted phonon dispersion calculation?

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Robin
Posts: 61
Joined: Thu Jan 14, 2010 3:18 am

Reuse DENx in an interrupted phonon dispersion calculation?

Post by Robin » Wed Aug 10, 2011 8:30 am

Dear developers,

In a phonon band structure calculation, if ABINIT is stopped before a DDB files is produced, there is no easy way (I think) to reuse the useful written results but restarting the DATASET from ground. I encounter this issue several times and it is really disappointing.

According to literature [eqn. 10 and 86, Rev. Mod. Phys. 73, 515 (2001)], this calculation only needs two crucial files: the electron density and its derivative to nucleus displacements, the later of which are written after each perturbation. So I want to know if you can implement a code to reuse the existing _DENx files in the phonon calculation. Maybe by enhancing the ability of ird1den?

Sincerely,
Guangfu Luo

mverstra
Posts: 655
Joined: Wed Aug 19, 2009 12:01 pm

Re: Reuse DENx in an interrupted phonon dispersion calculati

Post by mverstra » Tue Oct 11, 2011 10:22 pm

Hello Guangfu,

we are also trying this, and in short it does not work yet.

1) for self-consistent phonon calculation continuation, the density is not used at all, the initial wf are random

2) you could try to get better wf from a non-scf calculation (still using the 1DEN). This should work, but there are some problems with certain terms of the energy not being calculated correctly in the iscf < 0 case. It appears to us that even the potential is not quite right (in principle all you need is the 1DEN) either.

If you manage something I would be very interested.

Matthieu
Matthieu Verstraete
University of Liege, Belgium

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