The ABINIT Users Mailing List ( CLOSED )

[dominik.fischer@qimonda.com]

Dear all,
as far as I know this alternative way to calculate the dielectric constant 
that Xavier mentions 
(http://www.abinit.org/wws/arc/forum/2007-09/msg00039.html) (by relaxing the 
ions in an electric field) was so far only rarely used in the literature 
(e.g. Umari et al., PRL 89, 157602 (2002)).
I guess the input files tffield_7.in in the RF1 Tutorial corresponds to this 
approach. Unfortunately this example does not seem to work at least not on my 
computer and the problem was also discussed here 
http://www.abinit.org/wws/arc/forum/2007-05/msg00085.html

The error message is like this

 scfcv (electric field calculation) : WARNING -
   The difference between pel (electronic Berry phase updated
   at each SCF cycle)
   and pel_cg (electronic Berryphase computed using the berryphase routine) is
   pdif_mod =  0.622575664E-04

The problem occurs only when the ions are relaxed, if the ions are kept fixed 
(tffield_6.in) everything works and allows the extraction of the 
high-frequency dieletric constant.

Apparently ABINIT is in principle capable of doing these calculations however 
it doesn't work in the current implementation (I checked v4 and v5, neither 
works).
Has anybody found a trick or workaround to make this feature work? 

Regards,
Dominik