[Pw_forum] matdyn error

[Eduardo Ariel Menendez P]

Hello,
I have calculated a phonon band diagram using a 5x5x1 q-points mesh. It is
slightly different from a published one that was calculated using the
force-constants method using in 1x1x1 supercell (i.e., no supercell at
all). Then, in order to compare, I tried to calculate the phonon band
with ESPRESSO 2.1.2 using a 1x1x1
q-point mesh (i.e. only gamma point.) I generated the force constants
file, which heads

tisic111.fc
  3   12  4  5.7778399  0.0000000  5.7640220  0.0000000  0.0000000  0.0000000
           1  'Ti '    43624.5074822987
           2  'Si '    25596.2050112520
           3  'C  '    10946.2315865854
    1    1      0.0000000      0.0000000      0.0000000
    2    1      0.0000000      0.0000000      2.8820110
    3    1      0.5000005      0.2886748      0.7810250
    4    1     -0.0000005      0.5773506      3.6630360
    5    1     -0.0000005      0.5773506      4.9829970
    6    1      0.5000005      0.2886748      2.1009860
    7    2      0.0000000      0.0000000      1.4410055
    8    2      0.0000000      0.0000000      4.3230165
    9    3     -0.0000005      0.5773506      0.4161624
   10    3      0.5000005      0.2886748      3.2981734
   11    3      0.5000005      0.2886748      5.3478596
   12    3     -0.0000005      0.5773506      2.4658486
 F
   1   1   1
   1   1   1   1
   1   1   1   2.71801440000E-01
.....etc

and then run matdyn with the input

 &input
    asr=.true.,dos=.false.,ntyp=3,
    amass(1)=47.8671,
    amass(2)=28.0855,
    amass(3)=12.01078,
    flfrc='tisic111.fc', flfrq='tisic.freq'
 /
 459
0.000    0.000    0.000
0.000    0.000    0.00510295
....etc

and matdyn stops with this error

  0.900000000000000


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     from frc_blk : error #         1
     wrong total_weight

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

     stopping ...
2

What happens here? I tried with the example 06 (AlAs) and only gamma
point, and it works. I also tried to specify a general lattice with
ibrav=14, that is, changing the first line of the force-constant file as
follows

  3   12 14  5.7778399  1.0000000  5.7640220  1.0000000  1.0000000 -0.5000000
instead of
  3   12  4  5.7778399  0.0000000  5.7640220  0.0000000  0.0000000  0.000000

In this case I found a different error in matdyn:


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     from q_gen : error #         1
      probably nr1,nr2,nr3 too small

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

     stopping ...
2


Thanks,
Eduardo


Eduardo A. Menendez Proupin
Department of Physics
Faculty of Science
University of Chile
Las Palmeras 3425
Ñuñoa, Santiago
Chile
Phone: 56+2+678 74 11
http://fisica.ciencias.uchile.cl/~emenendez/