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<DIV><FONT face=Verdana><FONT size=2>Dear PWSCF users,</FONT></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana><FONT size=2> I'm trying to
calculate the electronic properties of rhombohedral BiFeO3 under R3C
</FONT></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana><FONT size=2>symmetry group. The wychoff position is
Bi(2b)(0 0 0),Fe(2a)(0.221 0.221 0.221),O(6e)(0.538 </FONT></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana><FONT size=2>0.933 0.395), hence under R3C group
symmetry the atomic position should be<BR>Bi
0.00000 0.00000
0.00000<BR>Bi 0.50000
0.50000 0.50000<BR>Fe
0.22100 0.22100
0.22100<BR>Fe
0.72100 0.72100
0.72100 <BR>O
0.53800 0.93300
0.39500<BR>O
0.39500 0.53800
0.93300<BR>O
0.93300 0.39500
0.53800<BR>O
1.43300 1.03800
0.89500<BR>O
1.03800 0.89500 1.43300
<BR>O 0.89500
1.43300 1.03800</FONT></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana><FONT size=2>When I set the ATOMIC_POSITIONS in alat
unit the code gave no symmetry, and the code </FONT></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana><FONT size=2>produced wrong symmertry ( not R3c group)
with the ATOMIC_POSITIONS in crystal unit.</FONT></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana><FONT size=2>Acturally in crystal unit the triplet
coordinates should be less than 1, but in my case the </FONT></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana><FONT size=2>1.433 was obviously wrong, but O(6e)(0.538
0.933 0.395) under R3C will definitely produce </FONT></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana><FONT size=2>the value above. I have encountered this
problem for a long time, could anyone point the </FONT></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana><FONT size=2>wrong place in my case? Any sugestions will
be very appreciated.</FONT></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana><FONT size=2>My input file was pasted
below:<BR>&control<BR>calculation='scf'<BR>restart_mode='from_scratch',<BR>verbosity='high',<BR>prefix='bifo',<BR>pseudo_dir='./',<BR>outdir='./'<BR>/<BR> &system<BR>ibrav=
5, celldm(1)= 10.6427, celldm(4)= 0.5, nat= 10, ntyp=
3,<BR>ecutwfc=35.0<BR>occupations =
'fixed'<BR>degauss=0.00<BR>nbnd=100<BR>lda_plus_u=.true.
Hubbard_U(2)=5,<BR>nspin=2,multiplicity=5,<BR>/<BR> &electrons<BR>mixing_beta=0.3,<BR>diagonalization='cg'<BR>/<BR>ATOMIC_SPECIES<BR>Bi
208.98 Bi.pbe-d-mt.UPF<BR>Fe 55.847
Fe.pbe-sp-van_ak.UPF<BR>O 15.999
O.pbe-van_ak.UPF<BR>ATOMIC_POSITIONS
{alat}<BR>Bi 0.00000
0.00000 0.00000<BR>Bi
0.50000 0.50000
0.50000<BR>Fe 0.22100
0.22100 0.22100<BR>Fe
0.72100 0.72100
0.72100 <BR>O
0.53800 0.93300
0.39500<BR>O
0.39500 0.53800
0.93300<BR>O
0.93300 0.39500
0.53800<BR>O
1.43300 1.03800
0.89500<BR>O
1.03800 0.89500 1.43300
<BR>O 0.89500
1.43300 1.03800<BR>K_POINTS {automatic}<BR>8 8 8 0
0 0 </FONT></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana><FONT size=2>Best Regards,</FONT></FONT></DIV>
<DIV> </DIV><FONT face=Verdana><FONT size=2>
<DIV><BR>Hongkien Feng</DIV>
<DIV> </DIV>
<DIV>Physics department,<BR>Beijing university of <BR>aeronautics and
astronautics<BR></FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV align=left><FONT size=2>
<HR style="WIDTH: 122px; HEIGHT: 2px" SIZE=2>
</FONT></DIV>
<DIV><FONT color=#c0c0c0><FONT size=2>fenghongjian</FONT></DIV>
<DIV><FONT size=2>2007-08-02</FONT></FONT></DIV></FONT></BODY></HTML>