[Pw_forum] matdyn.modes

Ion Errea ierrea001 at ikasle.ehu.es
Fri Nov 16 16:53:05 CET 2007


Dear all,

I'm calculating phonons in different points using ph.x q2r.x and
matdyn.x. Basically my problem is that when I get the results and want
to see the normal modes, in the file matyn.modes I do not understand the
meaning of all rows. There are 6 different rows for each phonon. That is
for one phonon (there are 6 atoms per unit cell) at a given K point I
get

  q =       0.5333      0.0667      0.0000
**************************************************************************
     omega( 1) =       5.975199 [THz] =     199.312497 [cm-1]
0.000000   0.000000     0.000000   0.000000     0.468260  -0.006324   
0.000000   0.000000     0.000000   0.000000    -0.270615   0.382197   
0.000977  -0.014434    -0.003796   0.056105    -0.089053  -0.006026   
-0.000977   0.014434     0.003796  -0.056105    -0.089053  -0.006026  
0.000000   0.000000     0.000000   0.000000    -0.294161   0.427580   
0.000000   0.000000     0.000000   0.000000     0.518994   0.000000   

The rows 1,3,5 I understand that give the displacement of the atoms.
However I don't know what the even ones mean. Normally I get 0.0000000
for these, but not in my lst calculations in agiven system. I wonder if
anyone can help me to undesrtand the meaning of these even rows and let
me know wheter this non-zero result is worrying.

Thanks a lot for your attention.

====================================================================
Ion Errea Lope
Department of Condensed Matter, Unibersity of the Basque Country
Apdo. 644
48080 Bilbao (Spain)
Tlf: +34 94 601 5322





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