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<DIV>Dear All,</DIV>
<DIV> </DIV>
<DIV></DIV>
<DIV>I plan to do some postprocessing using the ground state wavefunctions at
k(+q)-mesh. So I tried to output the wavefunctions in the phonon code. Because I
want to know the wavefunctions at every k(+q) point instead of just the
irreducible Brillouin zone, I turnned off the symmetry (in pw code, by setting
<STRONG>nosym_evc=.true. </STRONG>and<STRONG> noinv=.true.</STRONG>). But then
the wavefunctions completely changed. The results I get from the output of evc
and evq in phq_init are:</DIV>
<DIV> </DIV>
<DIV></DIV>
<DIV><STRONG>when symmetry is active:</STRONG></DIV>
<DIV>
<DIV>q = ( 0.000000000000000E+000 , 0.000000000000000E+000
,<BR>0.000000000000000E+000 )<BR>nksq =
20<BR>************************************************<BR>npol = 1<BR>npwx =
411<BR>nbnd = 4<BR>ik # = 1
-----------------------------------<BR>0.69783903837624816635E+00
-0.64649301435265482674E+00 0.69783903837624816635E+00
-0.64649301435265482674E+00<BR>-0.19216558783363027322E-16
0.87586028340881804830E-16 -0.19216558783363027322E-16
0.87586028340881804830E-16<BR>0.55275566596732210915E-16
0.32076646606791784316E-17 0.55275566596732210915E-16
0.32076646606791784316E-17<BR>0.23060842986941295573E-17
-0.42753486774548910442E-16 0.23060842986941295573E-17
-0.42753486774548910442E-16<BR>0.99051076923549141728E-01
0.37832014530605620820E-02 0.99051076923549141728E-01
0.37832014530605620820E-02<BR>......(these shows the first several numbers for G
at k=0,q=0,ibnd=1,ig=1..ngm)</DIV>
<DIV>nksq is the total k point that is considered.</DIV>
<DIV> </DIV>
<DIV></DIV>
<DIV><STRONG>When symmetry is turnned off:</STRONG></DIV>
<DIV>
<DIV>q = ( 0.000000000000000E+000 , 0.000000000000000E+000
,<BR>0.000000000000000E+000 )<BR>nksq =
343<BR>************************************************<BR>npol = 1<BR>npwx =
411<BR>nbnd = 4<BR>ik # = 1
-----------------------------------<BR>-0.49664369043450279362E+00
0.81134307529730043118E+00 -0.49664369043450279362E+00
0.81134307529730043118E+00<BR>-0.27818613173485040276E-10
0.54661997423613342026E-10 -0.27818613173485040276E-10
0.54661997423613342026E-10<BR>0.43853898353156132494E-10
-0.42976651079895819979E-10 0.43853898353156132494E-10
-0.42976651079895819979E-10<BR>0.63231205525296367916E-11
-0.10330070651313073490E-10 0.63231205525296367916E-11
-0.10330070651313073490E-10<BR>-0.96373137459236146718E-01
0.23187212493507927680E-01 -0.96373137459236146718E-01
0.23187212493507927680E-01<BR>.......(at k=0,q=0,ibnd=1,ig=1..ngm)</DIV>
<DIV> </DIV>
<DIV></DIV>
<DIV>However, the final result from phonon remains the same. So I want to know
which wavefunction I should use. Are they both correct? But then why they are so
different? (previously what I thought is that the wavefunction at other points
are just copies of those in the irreducible Brillouin zone, so the wavefunction
at gamma point should be the same, but maybe it turns out to a wrong
understanding..)</DIV>
<DIV> </DIV>
<DIV></DIV>
<DIV>I will appreciate a lot for your help. Thanks!</DIV>
<DIV> </DIV>
<DIV></DIV></DIV></DIV>
<DIV>BTW, The input file I use is:</DIV>
<DIV> </DIV>
<DIV></DIV>
<DIV>
<DIV><STRONG>pw.x:</STRONG></DIV>
<DIV></DIV>
<DIV>&control<BR>calculation= 'scf'<BR>wf_collect=.true.<BR>restart_mode=
'from_scratch'<BR>pseudo_dir= '/home/jiawei/pseudo/'<BR>outdir=
'/scratch/jiawei/silicon/'<BR>prefix=
'Si-ph-k7-e20-a10.21-pp:pz-vbc'<BR>tprnfor= .true.<BR>tstress=
.true.<BR>/<BR>&system<BR>ibrav= 2, celldm(1)= 10.21, nat= 2, ntyp=
1<BR>ecutwfc=20<BR>/<BR>&electrons<BR>conv_thr= 1.0d-12<BR>diagonalization=
'david'<BR>mixing_beta= 0.7<BR>/<BR>ATOMIC_SPECIES<BR>Si 28.0855
Si.pz-vbc.UPF<BR>ATOMIC_POSITIONS<BR>Si 0.00 0.00 0.00<BR>Si 0.25 0.25
0.25<BR>K_POINTS {automatic}<BR>7 7 7 0 0 0</DIV>
<DIV> </DIV>
<DIV></DIV>
<DIV><STRONG>ph.x:</STRONG></DIV>
<DIV></DIV>
<DIV>phonons of Si at
Gamma<BR>&inputph<BR>recover=.false.<BR>tr2_ph=1.0d-14<BR>prefix=
'Si-ph-k7-e20-a10.21-pp:pz-vbc'<BR>epsil=.false.<BR>ldisp=.false.<BR>amass(1)=28.0855<BR>outdir='/scratch/jiawei/silicon/'<BR>fildyn='Si.dyn'<BR>fildrho='Si.drhoG'<BR>/<BR>0.0
0.0 0.0<BR></DIV></DIV>
<DIV>Also, what I did to phonon code is adding some write lines inside
subroutine phq_init, where evc and evq are read from files and used to store
wavefunctions at k and k+q point for later the calculation.</DIV>
<DIV></DIV>
<DIV> </DIV>
<DIV>Best,</DIV>
<DIV> </DIV>
<DIV></DIV>
<DIV>Jiawei Zhou</DIV>
<DIV>Department of Mechanical Engineering</DIV>
<DIV>Massachusetts Institute of Technology</DIV>
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