On Sat, 2014-05-03 at 17:44 +0530, Saied Md Pratik wrote: > If I don't mention asr='zero-dim' in the input section then also I am > not getting the frequencies correctly. Now I am getting the following > frequencies
plot the corresponding modes and maybe you will understand why they are unstable P. > -------------------------------------- > # mode [cm-1] [THz] IR > 1 -132.06 -3.9590 0.1498 > 2 -131.77 -3.9503 0.1486 > 3 -109.35 -3.2782 0.0031 > 4 -108.74 -3.2599 0.0032 > 5 91.54 2.7443 0.0511 > 6 127.22 3.8141 0.0142 > 7 153.76 4.6095 0.0003 > 8 164.03 4.9174 5.4586 > 9 164.06 4.9185 5.4543 > 10 190.74 5.7182 4.0762 > 11 191.78 5.7493 0.0010 > 12 191.95 5.7544 0.6314 > 13 380.90 11.4192 0.0000 > 14 395.35 11.8522 0.0004 > 15 397.38 11.9132 0.0001 > 16 410.55 12.3081 0.0022 > 17 412.54 12.3677 0.0019 > 18 420.67 12.6114 0.0001 > 19 1398.48 41.9255 0.0328 > 20 1407.66 42.2007 5.2353 > 21 1408.10 42.2137 5.5635 > 22 1414.41 42.4029 0.0151 > 23 1414.84 42.4158 0.3427 > 24 1435.81 43.0446 7.0296 > 25 1635.17 49.0210 0.0000 > 26 1666.27 49.9536 0.0000 > 27 1685.50 50.5300 0.0001 > 28 1686.11 50.5484 0.0000 > 29 3052.32 91.5064 0.5011 > 30 3066.46 91.9303 3.0260 > 31 3082.41 92.4082 45.2275 > 32 3086.97 92.5451 19.4732 > 33 3091.92 92.6934 41.1318 > 34 3095.54 92.8020 33.9297 > 35 3103.29 93.0342 38.8619 > 36 3154.67 94.5747 67.2231 > -------------------------------------------------------------------- > > > Thanking you. > Pratik > > > > > On Fri, 2014-05-02 at 14:09 +0530, Saied Md Pratik wrote: > > > NH4Br crystal > > > asr='zero-dim' > > if it is a real crystal, you shouldn't use 'zero-dim'. > If it is a molecule in a supercell, you may have unstable > (and physically irrelevant) libration modes > > > celldm(1) = 1.890359168 > > putting into celldm(1) the a.u. to A conversion factor > is a bad habit in my opinion, and ot doesn't make sense > if you specify your cell vectors in A: > > > CELL_PARAMETERS angstrom > > 5.633079685 0.000000000 0.000000000 > > 0.000000000 5.633079685 0.000000000 > > 0.000000000 0.000000000 3.982678150 > > P. > > -- > Paolo Giannozzi, Dept. 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://pwscf.org/mailman/listinfo/pw_forum -- Paolo Giannozzi, Dept. Chemistry&Physics&Environment, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222
