[Pw_forum] phonon calculation crashes

[merlin meheut]

Dear all,

I have had a strange crash on a phonon calculation, with version  
3.2.3: I have calculated the dynamical matrix of the structure at  
gamma, at q-point (0;0.5;-0.5), both without problems, but I cannot  
calculate the (0;0;-1) q-point without having this error:


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
      from set_irr : error #         2
      npert > max_irr_dim
   
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

I don't know what this means. The structure I am calculating is very  
big (80 atoms), so maybe it is related, I don't know.

Follows the input files:

--------------------------- scf input file:
   pyrope    Pavese 1995 (30K) cubique centre
  &control
        calculation = 'scf',
       restart_mode = 'from_scratch' ,
             prefix = 'PYROPE',
            disk_io = 'default' ,
     pseudo_dir     = './',
     outdir         = '/tmp/',
     tprnfor        = .true.,
     tstress        = .true.,
/&end
&system
     ibrav =3, celldm(1)=21.9096,
     nat =80, ntyp = 4, ecutwfc = 80.0
/&end
  &electrons
    electron_maxstep = 60,
           conv_thr = 1.d-7 ,
        mixing_mode = 'plain',
        startingwfc = 'atomic',
        mixing_beta = 0.4,
    diagonalization = 'david_overlap',
/&end
ATOMIC_SPECIES
   Al   26.9815   Al.pbe2
   Mg   23.9850   Mgpbe1_mt.ncpp
   Si   27.9769   Si.pbe2
   O    15.9949   O.pbe
ATOMIC_POSITIONS crystal
Si     0.62500000   0.62500000   0.25000000
(...)

K_POINTS {crystal}
1
  0.25 0.25 0.25 1
-------------------------------------------------------------------

------------------------------------------nscf input file:

  pyrope    Pavese 1995 (30K) cubique centre
  &control
        calculation = 'phonon',
       restart_mode = 'from_scratch' ,
             prefix = 'PYROPE',
            disk_io = 'default' ,
     pseudo_dir     = './',
     outdir         = '/tmp/',
     tprnfor        = .true.,
     tstress        = .true.,
/&end
&system
     ibrav =3, celldm(1)=21.9096,
     nat =80, ntyp = 4, ecutwfc = 80.0
/&end
  &electrons
    electron_maxstep = 60,
           conv_thr = 1.d-7 ,
        mixing_mode = 'plain',
        startingwfc = 'atomic',
        mixing_beta = 0.4,
    diagonalization = 'david_overlap',
/&end
&phonon
xqq(1)= 0.0000000, xqq(2)= 0.0000000, xqq(3)= -1.0000000
/&end
ATOMIC_SPECIES
   Al   26.9815   Al.pbe2
   Mg   23.9850   Mgpbe1_mt.ncpp
   Si   27.9769   Si.pbe2
   O    15.9949   O.pbe
ATOMIC_POSITIONS crystal
Si     0.62500000   0.62500000   0.25000000
Si     0.87500000   0.87500000   0.75000000
(....)

K_POINTS {crystal}
1
  0.25 0.25 0.25 1
-------------------------------------------------------------------

-----------------------ph input file:

Pyrope m2
  &inputph
   amass(1)=26.9815,
   amass(2)=23.9850,
   amass(3)=27.9769,
   amass(4)=15.9949,
   alpha_mix(1) = 0.7,
    tr2_ph =  1.0D-16,
    prefix='PYROPE',
    fildyn='mat.strelD.bald.m3',
    epsil =.false.,
    trans =.true.,
    zue = .false.,
    outdir='/tmp/'
/&end
0.0 0.0 -1.0000000
-----------------------------------------------------


Has anyone an idea on the importance or the origin of this error?

Thanks for any hints,

Best regards,

Merlin Meheut

ESS department at UCLA








--
Merlin Méheut
professional adress:
595 Charles Young Drive East
3806 Geology Building
Los Angeles, California 90095-1597
United States of America
tel: 310 825 7934
cell phone: 310 893 4253

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