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<p>Dear Quantum Espresso community,</p>
<p>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:</p>
<p><i>Error in routine set_irr_sym_new</i></p>
<p><i>wrong representation</i></p>
<p>I am using version 6.2.1.<br>
<i></i></p>
<p>I've seen that this problem has come up before but there wasn't
always a working solution for it.</p>
<p>I have tried increasing the threshold which sends the error in
set_irr_sym.f90 as sometimes suggested. <br>
</p>
<p>I have also tried generating different random matrices (created
by random_matrix_new()) by changing the random number generator
seed, using uniformly distributed numbers</p>
<p>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</p>
<p>atom positions slightly.</p>
<p>I'd be thankful for any other suggestions.<br>
</p>
<p><br>
</p>
<p>Cheers,</p>
<p>Noé Mascello</p>
<p>ETH Zurich</p>
<p><br>
</p>
<p>________________________________________</p>
<p>scf input</p>
<p>&CONTROL<br>
calculation = 'scf'<br>
restart_mode = 'from_scratch'<br>
prefix = 'P4ncc_00'<br>
pseudo_dir = '/pps'<br>
outdir = './'<br>
/<br>
&SYSTEM<br>
ibrav = 6<br>
A = 5.28231<br>
B = 5.28231<br>
C = 7.84336<br>
cosAB = 0<br>
cosAC = 0<br>
cosBC = 0<br>
nat = 16<br>
ntyp = 2<br>
ecutwfc = 90<br>
occupations = 'smearing'<br>
degauss = 7.35d-4<br>
<br>
/<br>
&ELECTRONS<br>
conv_thr = 1.0d-8<br>
diagonalization = 'cg'<br>
/<br>
<br>
ATOMIC_SPECIES<br>
W 183.84 W_ONCV_PBE-1.1.upf<br>
O 15.9994 O_ONCV_PBE-1.0.upf<br>
<br>
<br>
ATOMIC_POSITIONS crystal<br>
W 0.250000000 0.250000000 0.219699999<br>
W 0.749999977 0.749999977 0.780300001<br>
W 0.749999977 0.749999977 0.280300031<br>
W 0.250000000 0.250000000 0.719699969<br>
O 0.250000000 0.250000000 0.493539985<br>
O 0.749999977 0.749999977 0.506460015<br>
O 0.749999977 0.749999977 0.006460011<br>
O 0.250000000 0.250000000 0.993540015<br>
O 0.460340007 0.539659993 0.250000000<br>
O 0.539659993 0.460340007 0.749999985<br>
O 0.039660007 0.960340007 0.250000000<br>
O 0.960340007 0.039659976 0.749999985<br>
O 0.960340007 0.460340007 0.250000000<br>
O 0.039659976 0.539659993 0.749999985<br>
O 0.539659993 0.039660007 0.250000000<br>
O 0.460340007 0.960340007 0.749999985<br>
<br>
K_POINTS automatic<br>
8 8 6 0 0 0</p>
<p>_______________________________<br>
</p>
<p>ph.x input (2nd q-point):</p>
<p><br>
&INPUTPH<br>
prefix = 'P4ncc_00'<br>
outdir = './q2'<br>
fildyn = 'P4ncc_00.dyn'<br>
fildvscf = 'dvscf'<br>
ldisp = .true.<br>
nq1 = 4<br>
nq2 = 4<br>
nq3 = 3<br>
asr = .true.<br>
tr2_ph = 1.0d-14<br>
start_q = 2<br>
last_q = 2<br>
recover = .true.<br>
search_sym = .false.<br>
/<br>
<br>
</p>
<p><br>
</p>
<p><br>
</p>
<p><br>
</p>
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