<br> Dear QE users,<br> <br> QE is able to find the correct symmetry for the input file, added at the end of this email.<br> Here is the proof:<br> 48 Sym.Ops. (with inversion). <br><br> However, during vc-relax it breaks the symmetry.<br>
 Proof goes here:<br>
   0.000000000   0.000000000   0.000000000<br>   0.250189867   0.250189867   0.250189867<br>   0.000000000   0.250189689   0.250189689<br>   0.250189689   0.000000000   0.250189689<br>   0.250189689   0.250189689   0.000000000<br>
   0.500379494   0.000000000   0.000000000<br>   0.750569121   0.250189867   0.250189867<br>   0.500379494   0.250189728   0.250189728<br>   0.750569299   0.000000000   0.250189689<br>   0.750569299   0.250189689   0.000000000<br>
   0.000000000   0.500379494   0.000000000<br>   0.250189867   0.750569121   0.250189867<br>   0.000000000   0.750569299   0.250189689<br>   0.250189728   0.500379494   0.250189728<br>   0.250189689   0.750569299   0.000000000<br>
   0.500379494   0.500379494   0.000000000<br>   0.750569121   0.750569121   0.250189867<br>   0.500379494   0.750569260   0.250189728<br>   0.750569260   0.500379494   0.250189728<br>   0.750569299   0.750569299   0.000000000<br>
   0.000000000   0.000000000   0.500379494<br>   0.250189867   0.250189867   0.750569121<br>   0.000000000   0.250189689   0.750569299<br>   0.250189689   0.000000000   0.750569299<br>   0.250189728   0.250189728   0.500379494<br>
   0.500379494   0.000000000   0.500379494<br>   0.750569121   0.250189867   0.750569121<br>   0.500379494   0.250189728   0.750569260<br>   0.750569299   0.000000000   0.750569299<br>   0.750569260   0.250189728   0.500379494<br>
   0.000000000   0.500379494   0.500379494<br>   0.250189867   0.750569121   0.750569121<br>   0.000000000   0.750569299   0.750569299<br>   0.250189728   0.500379494   0.750569260<br>   0.250189728   0.750569260   0.500379494<br>
   0.500379494   0.500379494   0.500379494<br>   0.750569121   0.750569121   0.750569121<br>   0.500379494   0.750569260   0.750569260<br>   0.750569260   0.500379494   0.750569260<br>   0.750569260   0.750569260   0.500379494<br>
<br><br>  Is this possible to keep symmetry of the initial system conserved during vc-relax with BFGS ?<br>  <br>  Input file:<br>    &control<br>    calculation='vc-relax'<br>    restart_mode='from_scratch',<br>
    prefix='pbmno',<br>    tstress = .true.<br>    tprnfor = .true.<br>    wf_collect=.true.<br>    verbosity='high'<br>    etot_conv_thr=1.0D-5, <br>    forc_conv_thr=1.0D-4,<br>
 /<br>  &system<br>    ibrav =  1,<br>    nat = 40,<br>    ntyp=3,<br>    celldm(1)=20.70<br>    nosym=.FALSE.<br>    ecutwfc = 30.0,<br>        ecutrho = 240.0,<br>    occupations='smearing',<br>    smearing='fd',<br>

    degauss=0.005d0,<br>    nspin=2<br>      starting_magnetization(2)=1.0,<br> /<br> &electrons<br>    diagonalization = 'david'<br>    conv_thr =  1.0d-9<br>    mixing_beta = 0.7<br> /<br> &ions<br> /<br>

 &cell<br> /<br>ATOMIC_SPECIES<br> Pb   1.0        Pb.UPF<br> Mn   1.0       Mn.UPF<br> O     1.0       O.UPF<br>ATOMIC_POSITIONS (alat)<br>Pb         0.00  0.00  0.00<br>
Mn         0.25  0.25  0.25<br>O          0.00  0.25  0.25<br>O          0.25  0.00  0.25<br>O          0.25  0.25  0.00<br>Pb          0.50  0.00  0.00<br>Mn          0.75  0.25  0.25<br>O         0.50  0.25  0.25<br>
O          0.75  0.00  0.25<br>O          0.75  0.25  0.00<br>Pb          0.00  0.50  0.00<br>Mn          0.25  0.75  0.25<br>O         0.00  0.75  0.25<br>O          0.25  0.50  0.25<br>O          0.25  0.75  0.00<br>
Pb          0.50  0.50  0.00<br>Mn          0.75  0.75  0.25<br>O         0.50  0.75  0.25<br>O          0.75  0.50  0.25<br>O          0.75  0.75  0.00<br>Pb          0.00  0.00  0.50<br>Mn          0.25  0.25  0.75<br>

O         0.00  0.25  0.75<br>O          0.25  0.00  0.75<br>O          0.25  0.25  0.50<br>Pb          0.50  0.00  0.50<br>Mn          0.75  0.25  0.75<br>O         0.50  0.25  0.75<br>O          0.75  0.00  0.75<br>
O          0.75  0.25  0.50<br>Pb          0.00  0.50  0.50<br>Mn          0.25  0.75  0.75<br>O         0.00  0.75  0.75<br>O          0.25  0.50  0.75<br>O          0.25  0.75  0.50<br>Pb          0.50  0.50  0.50<br>
Mn          0.75  0.75  0.75<br>O         0.50  0.75  0.75<br>O          0.75  0.50  0.75<br>O          0.75  0.75  0.50  <br>K_POINTS {automatic}<br> 2 2 2  0 0 0<br><br>Thanking you and with my best regards,<br>Srijan K<br>
CCMT<br>Indian Institute of Science<br>India 560012<br><br>