The ABINIT Users Mailing List ( CLOSED )

[Matthieu Verstraete <mjv500@york.ac.uk>]

Yes, Abinit adds a constant charge (jellium) to compensate the charge you 
say is in the cell. This only influences the G=0 term in the potential, 
which is not actually used in the way the Ewald sums are evaluated. 
Nevermind the details, the average electrostatic potential is set to 0.

This is only a 0th order approximation, and converges very slowly with 
system size, so watch the convergence of your quantities wrt the amount of 
bulk around the defect. Higher order corrections exist (Makov and Payne, 
Peter Schultz - both in prb somewhere, and others) but are not implemented 
in abinit. Soon there may be a wavelet based algorithm in abinit which 
will be able to deal with charged cells cleanly. No timeline on that yet, 
though.

Matthieu

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Dr. Matthieu Verstraete                 mailto:mjv500@york.ac.uk
Dept. of Physics, University of York,     tel: +44 1904 43 22 08
Heslington, YO10 5DD York, United Kingdom fax: +44 1904 43 22 14