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<p>Dear all,</p>
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<p>I have been trying to calculate el-ph coupling constant for monolayer MoTe2 using QE and EPW.
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<p>While calculating the phonon energies using ph.x I get error as <br>
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<p><br>
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<p></p>
<div> task # 3<br>
from divide_class : error # 1<br>
Wrong classes for C_3v</div>
<div><br>
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<div>But when I add the tag search_sym=.FALSE. as directed in this <a href="https://lists.quantum-espresso.org/pipermail/users/2017-August/039055.html" class="OWAAutoLink" id="LPlnk176340" previewremoved="true">
https://lists.quantum-espresso.org/pipermail/users/2017-August/039055.html</a>, I am able to calculate the phonon energies.</div>
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<div>But, when I try to calculate el-ph coupling constant using EPW, I get the same error. Is there any way to switch off symmetry in EPW or other ways to overcome this error in ph.x?</div>
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<div>My scf input file <br>
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<div>&CONTROL<br>
calculation='scf',<br>
outdir='./',<br>
prefix='calc',<br>
pseudo_dir='./',<br>
verbosity='low',<br>
wf_collect= .true.<br>
/<br>
<br>
&SYSTEM<br>
<br>
ibrav=0,<br>
nat= 3, ntyp= 2, nbnd= 27,<br>
ecutwfc = 60, ecutrho=240,<br>
occupations = 'fixed'<br>
<br>
/<br>
<br>
&ELECTRONS<br>
conv_thr=1d-9,<br>
mixing_beta=0.7d0,<br>
/<br>
ATOMIC_SPECIES<br>
<br>
Mo 95.96 Mo_ONCV_PBE_sr.upf<br>
Te 127.6 Te_ONCV_PBE_sr.upf<br>
<br>
ATOMIC_POSITIONS (crystal)<br>
Mo 0.333333015000d0 0.333333015000d0 0.154510160000d0<br>
Te 0.666666985000d0 0.666666985000d0 0.226882756000d0<br>
Te 0.666666985000d0 0.666666985000d0 0.082149790000d0<br>
<br>
K_POINTS {automatic}<br>
12 12 1 0 0 0<br>
<br>
CELL_PARAMETERS (angstrom)<br>
1.779701562000d0 3.082533129000d0 0.000000000000d0<br>
-1.779701562000d0 3.082533129000d0 0.000000000000d0<br>
0.000000000000d0 0.000000000000d0 25.000000000000d0</div>
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<div>and ph.x input file</div>
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<div>MoTe2_phonon<br>
&inputph<br>
recover=.true.,<br>
tr2_ph=1.0d-16,<br>
prefix='calc',<br>
fildvscf='dvscf',<br>
amass(1)=95.960d0<br>
amass(2)=127.60d0<br>
outdir='./',<br>
ldisp=.true.,<br>
nq1=6,nq2=6,nq3=1,<br>
fildyn='calc.dyn',</div>
<div> search_sym=.FALSE.<br>
/</div>
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<div>Thank you</div>
<div>Sanjay Gopalan</div>
<div>Research Assistant</div>
<div>University of Texas at Dallas<br>
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