[QE-users] Still not a group! symmetry disabled

[mkondrin]

Dear QE developers and users!

I have encountered a strange error. It did not produce CRASH file in the 
working directory but the job stops. In the end of output file there are 
error messages:

      Program PWSCF v.6.4 starts on 27May2020 at 15:10: 5

      This program is part of the open-source Quantum ESPRESSO suite
      for quantum simulation of materials; please cite
          "P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009);
          "P. Giannozzi et al., J. Phys.:Condens. Matter 29 465901 (2017);
           URL http://www.quantum-espresso.org",
      in publications or presentations arising from this work. More 
details at
      http://www.quantum-espresso.org/quote

      Parallel version (MPI), running on     8 processors
      R & G space division:  proc/nbgrp/npool/nimage =       8
      Waiting for input...
      Reading input from standard input

      Current dimensions of program PWSCF are:
      Max number of different atomic species (ntypx) = 10
      Max number of k-points (npk) =  40000
      Max angular momentum in pseudopotentials (lmaxx) =  3
                file C.pbe-mt_fhi.UPF: wavefunction(s)  4f renormalized

      Subspace diagonalization in iterative solution of the eigenvalue 
problem:
      one sub-group per band group will be used
      scalapack distributed-memory algorithm (size of sub-group:  2* 2 
procs)

      Message from routine find_sym:
      Not a group! Trying with lower acceptance parameter...
      Message from routine find_sym:
      Still not a group! symmetry disabled

  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
      Error in routine  good_fft_order (2050):
       fft order too large
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

      stopping ...

The imput file is attached below. However, if I  change the coordinate 
of last atom to:

C   0.500000000000000   0.875000000000000   0.777857142857143

the job completes OK.

Sincerely yours,
M. V. Kondrin

&control
title='An (100) twin',
calculation='vc-relax',
prefix='twin',
tstress=.true.,
tprnfor=.true.,
disk_io='low',
pseudo_dir = '../../../QE/pseudo',
outdir='./tmp'
/
&SYSTEM
   ibrav = 0
   A =   2.5200
   nat = 32
   ntyp = 1
   tot_charge=0,
   ecutwfc=70,
   occupations='smearing',
   smearing='methfessel-paxton',
   degauss=0.02
/
&electrons
     mixing_beta = 0.7,
     conv_thr =  1.0d-5
/
&ions
/
&cell
cell_factor=4,
press=0.0
/
ATOMIC_SPECIES
    C   12.01060    C.pbe-mt_fhi.UPF

K_POINTS {automatic}
2 2 1 0 0 0

CELL_PARAMETERS {alat}
   1.000000000000000   0.000000000000000   0.000000000000000
   0.000000000000000   2.000000000000000   0.000000000000000
   0.000000000000000   0.000000000000000   5.950000000000000

ATOMIC_POSITIONS {crystal}
C   0.500000000000000   0.875000000000000   0.208333333333333
C   0.000000000000000   0.125000000000000   0.089285714285714
C   0.500000000000000   0.025000000000000   0.029761904761905
C   0.000000000000000   0.875000000000000   0.148809523809524
C   0.500000000000000   0.775000000000000   0.446428571428571
C   0.000000000000000   0.125000000000000   0.327380952380952
C   0.500000000000000   0.125000000000000   0.267857142857143
C   0.000000000000000   0.875000000000000   0.386904761904762
C   0.000000000000000   0.625000000000000   0.089285714285714
C   0.500000000000000   0.375000000000000   0.208333333333333
C   0.000000000000000   0.375000000000000   0.148809523809524
C   0.500000000000000   0.725000000000000   0.029761904761905
C   0.000000000000000   0.625000000000000   0.327380952380952
C   0.500000000000000   0.475000000000000   0.446428571428571
C   0.000000000000000   0.375000000000000   0.386904761904762
C   0.500000000000000   0.625000000000000   0.267857142857143
C   0.500000000000000   0.125000000000000   0.708333333333333
C   0.000000000000000   0.375000000000000   0.589285714285714
C   0.500000000000000   0.275000000000000   0.529761904761905
C   0.000000000000000   0.125000000000000   0.648809523809524
C   0.500000000000000   0.225000000000000   0.946428571428571
C   0.000000000000000   0.375000000000000   0.827380952380952
C   0.500000000000000   0.375000000000000   0.767857142857143
C   0.000000000000000   0.125000000000000   0.886904761904762
C   0.000000000000000   0.875000000000000   0.589285714285714
C   0.500000000000000   0.625000000000000   0.708333333333333
C   0.000000000000000   0.625000000000000   0.648809523809524
C   0.500000000000000   0.975000000000000   0.529761904761905
C   0.000000000000000   0.875000000000000   0.827380952380952
C   0.500000000000000   0.525000000000000   0.946428571428571
C   0.000000000000000   0.625000000000000   0.886904761904762
C   0.500000000000000   0.875000000000000   0.767857142857143