The Isotropy Software has a module, called SMODES, that does a full analysis of phonon modes; including their Raman/Infrared activity. It uses 'simple' group theory only, and the only input it needs is the structure: Therefore, it cannot be affected by any lack of convergence or other errors in the DF(P)T calculation. I suggest always using SMODES -before- doing a phonon calculation to know what to expect.
You can access SMODES at http://stokes.byu.edu/smodes.html Best, Turan. ------- PhD Candidate, Cornell University On Sat, Dec 3, 2011 at 5:10 AM, Paolo Giannozzi <giannozz at democritos.it> wrote: > > On Dec 2, 2011, at 18:32 , HASAN SAHIN wrote: > >> ? ? ?omega( ?4 - ?5) ? = ? ? ? ? 102.9 ?[cm-1] ? --> E >> L_3 ? ? ? ? ?I+R >> ? ? ?omega( ?6 - ?7) ? = ? ? ? ? 156.9 ?[cm-1] ? --> E >> L_3 ? ? ? ? ?I+R >> ? ? ?omega( ?8 - ?8) ? = ? ? ? ? 402.0 ?[cm-1] ? --> A_1 >> L_1 ? ? ? ?I+R >> ? ? ?omega( ?9 - 10) ?= ? ? ? ? 719.8 ?[cm-1] ? --> E >> L_3 ? ? ? ? ?I+R >> ? ? ?omega( 11 - 11) = ? ? ? ? 831.9 ?[cm-1] ? --> A_1 ?L_1 ? ? ? ?I+R >> ? ? ?omega( 12 - 12) = ? ? ? 1042.2 ?[cm-1] ? --> A_1 ?L_1 ? ? ? ?I+R > > no inversion symmetry > >> ? ? ?omega( ?4 - ?5) ? = ? ? ? ?104.8 ?[cm-1] ? --> E_g >> L_3 ? ? ? ? ?R >> ? ? ?omega( ?6 - ?7) ? = ? ? ? ?165.5 ?[cm-1] ? --> E_u >> L_3' ? ? ? ? I >> ? ? ?omega( ?8 - ?8) ? = ? ? ? ?398.5 ?[cm-1] ? --> A_1g L_1 ? ? ? ? R >> ? ? ?omega( ?9 - 10) ?= ? ? ? ?715.3 ?[cm-1] ? --> E_g ?L_3 ? ? ? ? ?R >> ? ? ?omega( 11 - 11) = ? ? ? ?827.6 ?[cm-1] ? --> A_2u L_2' ? ? ? ?I >> ? ? ?omega( 12 - 12) = ? ? ? 1042.5 ?[cm-1] ? --> A_1g L_1 ? ? ? ?R > > inversion symmetry (note the "g" and "u", standing for "gerade", even, > and "ungerade", odd). In presence of inversion symmetry, Raman-active > modes are even, Infrared-active modes are odd > > 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 > > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum
