On Thursday 07 September 2006 16:01, Axel Kohlmeyer wrote: > > how about including several atoms in the neighborhood of the > adsorbed molecule? this is how it works in CPMD: you pick an > atom (or pick a reference coordinate) and set a radius and then > do the vibrational analysis for those atoms and keep the rest fixed. > this way you include at least the contributions from the near > neighbors, have the rest as 'static background', and still save > a lot of (cpu) time.
the problem I see in this approach is that the vibrations of surface atoms close to the adsorbed molecule may be strongly correlated to vibrations of other atoms in the surface; i.e., taking only a few surface atoms close to the molecule will produce rather bogus displacement patterns for those atoms. Paolo -- Paolo Giannozzi Phone: +39/050-509876 DEMOCRITOS and SNS Fax: +39/050-563513 Piazza dei Cavalieri 7 I-56126 Pisa, Italy
