On Oct 20, 2012, at 12:59 , karan deep wrote: > still vibrational modes are different
they aren't > for sc it gives > > omega( 1 - 3) = 9.5 [cm-1] --> T_2 G_15 P_4 I+R this is the acoustic (zero-frequency) mode > omega( 22 - 24) = 510.2 [cm-1] --> T_2 G_15 P_4 I+R this is the optical mode. Al other zone-center modes of the sc lattice do not corrspond to zone-center modes of the fcc lattice. > for fcc it gives the same (zero-frequency mode do not have exactly zero frequency for reasons that have been explained too many times) P. --- Paolo Giannozzi, Dept of Chemistry&Physics&Environment, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222
