[QE-users] Error in ph.x: wrong representation

[Noé Mascello]

Dear Quantum Espresso community,

I have a structure where the phonon calculation for a single irreducible 
q-point fails (it works for all other q-points), rendering the error:

/Error in routine set_irr_sym_new/

/wrong representation/

I am using version 6.2.1.
//

I've seen that this problem has come up before but there wasn't always a 
working solution for it.

I have tried increasing the threshold which sends the error in 
set_irr_sym.f90 as sometimes suggested.

I have also tried generating different random matrices (created by 
random_matrix_new()) by changing the random number generator seed, using 
uniformly distributed numbers

and using normally distributed random numbers with different mean value 
and variance. Unfortunately, I always get the same error at this 
q-point. I also had no success with changing all

atom positions slightly.

I'd be thankful for any other suggestions.


Cheers,

Noé Mascello

ETH Zurich


________________________________________

scf input

&CONTROL
     calculation   = 'scf'
     restart_mode  = 'from_scratch'
     prefix        = 'P4ncc_00'
     pseudo_dir    = '/pps'
     outdir        = './'
/
&SYSTEM
     ibrav       = 6
     A           = 5.28231
     B           = 5.28231
     C           = 7.84336
     cosAB       = 0
     cosAC       = 0
     cosBC       = 0
     nat         = 16
     ntyp        = 2
     ecutwfc     = 90
     occupations = 'smearing'
     degauss     = 7.35d-4

/
&ELECTRONS
     conv_thr    = 1.0d-8
     diagonalization = 'cg'
/

ATOMIC_SPECIES
W 183.84 W_ONCV_PBE-1.1.upf
O 15.9994 O_ONCV_PBE-1.0.upf


ATOMIC_POSITIONS crystal
      W 0.250000000         0.250000000         0.219699999
      W 0.749999977         0.749999977         0.780300001
      W 0.749999977         0.749999977         0.280300031
      W 0.250000000         0.250000000         0.719699969
      O 0.250000000         0.250000000         0.493539985
      O 0.749999977         0.749999977         0.506460015
      O 0.749999977         0.749999977         0.006460011
      O 0.250000000         0.250000000         0.993540015
      O 0.460340007         0.539659993         0.250000000
      O 0.539659993         0.460340007         0.749999985
      O 0.039660007         0.960340007         0.250000000
      O 0.960340007         0.039659976         0.749999985
      O 0.960340007         0.460340007         0.250000000
      O 0.039659976         0.539659993         0.749999985
      O 0.539659993         0.039660007         0.250000000
      O 0.460340007         0.960340007         0.749999985

K_POINTS automatic
8 8 6 0 0 0

_______________________________

ph.x input (2nd q-point):


&INPUTPH
     prefix   = 'P4ncc_00'
     outdir   = './q2'
     fildyn   = 'P4ncc_00.dyn'
     fildvscf = 'dvscf'
     ldisp    = .true.
     nq1      = 4
     nq2      = 4
     nq3      = 3
     asr      = .true.
     tr2_ph   = 1.0d-14
     start_q = 2
     last_q = 2
     recover = .true.
     search_sym = .false.
/




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