On Sat, 2012-11-03 at 07:44 -0200, Antonio wrote: > I'm running a phonon calculation (at gamma point) for a system containing 81 > ions (243 modes), but allowing the displacement of only 13 ones (in order to > check out this approximation for my system). According to the output file, > there are 39 modes to be done. So, what do other frequencies shown mean?
I don't know much about the option you are using, but I think that it might be useful (maybe, and with care) only if you want to compare the vibrational modes of an isoolated molecule with those of the molecule adsorbed on a surface. In principle, what you get from the diagonalization of the partial dynamical matrix is meaningless. P. -- Paolo Giannozzi, IOM-Democritos and University of Udine, Italy
