Look at the displacement patterns: they correspond to rigid translations of all atoms. T_1u, G_15, G_4-, are symmetry labels (G stands for Gamma) for threefold degenerate odd-parity (u, -) irreducible representation of cubic groups.
P. On Tue, 2014-04-01 at 19:53 +0530, Peram sreenivasa reddy wrote: > Dear xirainbow, > > > Thank you very much for your replay. > > > > In my case.dyn1 file (given bellow), the omega(1), omega(2) and > omega(3) have same values as -16.572332 [cm-1]. In my plot i got > imaginary for only one mode along gamma to X direction. In case.ph.out > file the same only it is writing as bellow > > omega( 1 - 3) = -16.6 [cm-1] --> T_1u G_15 G_4- I > omega( 4 - 6) = 122.3 [cm-1] --> T_1u G_15 G_4- I > omega( 7 - 9) = 145.0 [cm-1] --> T_2g G_25' G_5+ R > omega( 10 - 12) = 258.5 [cm-1] --> T_1u G_15 G_4- I > > > My question is > > > I want to know among T_1u, G_15 and G_4- , which is belongs to that > imaginary one?. and This is due to which atom ?. > > > Here i am giving the case.dyn1 file > > Dynamical matrix file > > 3 4 2 12.9257258 0.0000000 0.0000000 0.0000000 0.0000000 > 0.0000000 > > 1 'X ' 83145.5895442744 > > 2 'Y ' 43628.1015381455 > > 3 'Z ' 24592.5885412130 > > 1 1 0.2500000 0.2500000 0.2500000 > 2 1 0.7500000 0.7500000 0.7500000 > 3 2 0.0000000 0.0000000 0.5000000 > 4 3 0.0000000 0.0000000 0.0000000 > > > > Diagonalizing the dynamical matrix > > q = ( 0.000000000 0.000000000 0.000000000 ) > > ************************************************************************** > omega( 1) = -0.496826 [THz] = -16.572332 [cm-1] > ( -0.474725 0.000000 -0.149266 0.000000 0.011949 0.000000 ) > ( -0.474725 0.000000 -0.149266 0.000000 0.011949 0.000000 ) > ( -0.478986 0.000000 -0.150606 0.000000 0.012057 0.000000 ) > ( -0.478907 0.000000 -0.150581 0.000000 0.012055 0.000000 ) > omega( 2) = -0.496826 [THz] = -16.572332 [cm-1] > ( 0.115254 0.000000 -0.389580 0.000000 -0.287630 0.000000 ) > ( 0.115254 0.000000 -0.389580 0.000000 -0.287630 0.000000 ) > ( 0.116289 0.000000 -0.393077 0.000000 -0.290211 0.000000 ) > ( 0.116269 0.000000 -0.393012 0.000000 -0.290163 0.000000 ) > omega( 3) = -0.496826 [THz] = -16.572332 [cm-1] > ( -0.095601 0.000000 0.271540 0.000000 -0.406095 0.000000 ) > ( -0.095601 0.000000 0.271540 0.000000 -0.406095 0.000000 ) > ( -0.096459 0.000000 0.273977 0.000000 -0.409740 0.000000 ) > ( -0.096443 0.000000 0.273932 0.000000 -0.409672 0.000000 ) > omega( 4) = 3.667733 [THz] = 122.342418 [cm-1] > ( -0.030936 0.000000 0.147451 0.000000 0.112884 0.000000 ) > ( -0.030936 0.000000 0.147451 0.000000 0.112884 0.000000 ) > ( 0.148268 0.000000 -0.706706 0.000000 -0.541030 0.000000 ) > ( -0.055722 0.000000 0.265593 0.000000 0.203329 0.000000 ) > omega( 5) = 3.667733 [THz] = 122.342418 [cm-1] > ( -0.178977 0.000000 -0.054189 0.000000 0.021734 0.000000 ) > ( -0.178977 0.000000 -0.054189 0.000000 0.021734 0.000000 ) > ( 0.857803 0.000000 0.259716 0.000000 -0.104167 0.000000 ) > ( -0.322379 0.000000 -0.097606 0.000000 0.039148 0.000000 ) > omega( 6) = 3.667733 [THz] = 122.342418 [cm-1] > ( 0.049515 0.000000 -0.103746 0.000000 0.149085 0.000000 ) > ( 0.049515 0.000000 -0.103746 0.000000 0.149085 0.000000 ) > ( -0.237317 0.000000 0.497237 0.000000 -0.714539 0.000000 ) > ( 0.089188 0.000000 -0.186871 0.000000 0.268537 0.000000 ) > omega( 7) = 4.346354 [THz] = 144.978757 [cm-1] > ( -0.661366 0.000000 -0.216095 0.000000 0.126085 0.000000 ) > ( 0.661366 0.000000 0.216095 0.000000 -0.126085 0.000000 ) > ( 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 ) > ( 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 ) > omega( 8) = 4.346354 [THz] = 144.978757 [cm-1] > ( 0.016908 0.000000 -0.394145 0.000000 -0.586825 0.000000 ) > ( -0.016908 0.000000 0.394145 0.000000 0.586825 0.000000 ) > ( 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 ) > ( 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 ) > omega( 9) = 4.346354 [THz] = 144.978757 [cm-1] > ( -0.249617 0.000000 0.545851 0.000000 -0.373816 0.000000 ) > ( 0.249617 0.000000 -0.545851 0.000000 0.373816 0.000000 ) > ( 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 ) > ( 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 ) > omega(10) = 7.750968 [THz] = 258.544478 [cm-1] > ( 0.152212 0.000000 0.015908 0.000000 -0.060146 0.000000 ) > ( 0.152212 0.000000 0.015908 0.000000 -0.060146 0.000000 ) > ( -0.069108 0.000000 -0.007223 0.000000 0.027308 0.000000 ) > ( -0.897629 0.000000 -0.093813 0.000000 0.354696 0.000000 ) > omega(11) = 7.750968 [THz] = 258.544478 [cm-1] > ( -0.060461 0.000000 0.075301 0.000000 -0.133092 0.000000 ) > ( -0.060461 0.000000 0.075301 0.000000 -0.133092 0.000000 ) > ( 0.027451 0.000000 -0.034188 0.000000 0.060427 0.000000 ) > ( 0.356551 0.000000 -0.444063 0.000000 0.784874 0.000000 ) > omega(12) = 7.750968 [THz] = 258.544478 [cm-1] > ( -0.014667 0.000000 -0.145314 0.000000 -0.075552 0.000000 ) > ( -0.014667 0.000000 -0.145314 0.000000 -0.075552 0.000000 ) > ( 0.006659 0.000000 0.065976 0.000000 0.034302 0.000000 ) > ( 0.086496 0.000000 0.856945 0.000000 0.445546 0.000000 ) > ************************************************************************** > > Thank you. > > > > > > On Tue, Apr 1, 2014 at 7:28 PM, xirainbow <nkxirainbow at gmail.com> > wrote: > Dear > In my calculation, the end of the *.dyn1 file looks like the > following content: > > " Diagonalizing the dynamical matrix > > q = ( 0.000000000 0.000000000 0.000000000 ) > > > ************************************************************************** > omega( 1) = XX [THz] = XX [cm-1] > ( 0.142825 0.000000 0.142825 0.000000 0.323621 0.000000 > ) > ( -0.142825 0.000000 -0.142825 0.000000 0.323621 0.000000 > ) > ( -0.142825 0.000000 0.142825 0.000000 0.323621 0.000000 > ) > ( 0.142825 0.000000 -0.142825 0.000000 0.323621 0.000000 > ) > omega( 2) = XX [THz] = XX [cm-1] > ( -0.226720 0.000000 0.264038 0.000000 -0.002735 0.000000 > ) > ( -0.226720 0.000000 0.264038 0.000000 0.002735 0.000000 > ) > ( -0.269604 0.000000 0.301664 0.000000 -0.041874 0.000000 > ) > ( -0.269604 0.000000 0.301664 0.000000 0.041874 0.000000 > ) > > ..................................." > > On Tue, Apr 1, 2014 at 7:49 PM, Peram sreenivasa reddy > <peramsreenivas at gmail.com> wrote: > > Dear xirainbow, > > > > Thank you very much for your replay. > > > > In that case.dyn1 file also it is giving same only as in the > case.ph.out > > file. > > > > Please give me more clarification. > > > > Thanking you. > > > > > > On Tue, Apr 1, 2014 at 3:15 PM, xirainbow > <nkxirainbow at gmail.com> wrote: > >> > >> You can find the answer at the end of *.dyn* files. > >> > >> On Mon, Mar 31, 2014 at 11:10 PM, Peram sreenivasa reddy > >> <peramsreenivas at gmail.com> wrote: > >> > Dear Pwscf, > >> > > >> > In my phonon calculations i got one imaginary mode in > gamma to X > >> > direction. > >> > I want to know which mode it is? and due to which atom it > is happening? > >> > > >> > I checked the case.ph.out file. In this file it is given > like below. > >> > > >> > Mode symmetry, O_h (m-3m) point group: > >> > omega( 1 - 3) = -16.6 [cm-1] --> T_1u G_15 > G_4- I > >> > omega( 4 - 6) = 122.3 [cm-1] --> T_1u G_15 > G_4- I > >> > omega( 7 - 9) = 145.0 [cm-1] --> T_2g G_25' > G_5+ R > >> > omega( 10 - 12) = 258.5 [cm-1] --> T_1u G_15 > G_4- I > >> > > >> > Here i am attaching the case.agr file > >> > > >> > Here all acoustic modes are given with same frequency. > How can know that > >> > particular mode name. > >> > > >> > > >> > My system is X2YZ type. How can i know this imaginary > mode is due to > >> > which > >> > atom. I plotted partial phonon density of states also. > But all atoms are > >> > giving same contribution in this acoustic mode region. > >> > > >> > Thank you in advance. > >> > > >> > > >> > > >> > _______________________________________________ > >> > Pw_forum mailing list > >> > Pw_forum at pwscf.org > >> > http://pwscf.org/mailman/listinfo/pw_forum > >> > >> > >> > >> -- > >> ____________________________________ > >> Hui Wang > >> School of physics, Henan University of Science and > Technology, Henan, > >> China > >> _______________________________________________ > >> Pw_forum mailing list > >> Pw_forum at pwscf.org > >> http://pwscf.org/mailman/listinfo/pw_forum > > > > > > > > > > > > > > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://pwscf.org/mailman/listinfo/pw_forum > > > > -- > ____________________________________ > Hui Wang > School of physics, Henan University of Science and Technology, > Henan, China > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum > > > > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum -- Paolo Giannozzi, Dept. 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