[Pw_forum] R-3c symmetry

[Fatma Litimein]

Dear all,

   I'm a new user and I'm trying to calculate the electronic properties 

of rhombohedral al2o3 under R-3C symmetry group. When I optimize 

these atoms, the code can't find the symmetry group (No symmetry !). 

I suspect that I must be doing something wrong here. Below is my input file.

Thanks in advance,

------------------------------------------------------------------------------------------- 
&control
calculation = "vc-relax" ,
restart_mode = 'from_scratch' ,
outdir='$TMP_DIR/' ,
pseudo_dir = '$PSEUDO_DIR' ,
disk_io = 'default' ,
verbosity = 'default' ,
tstress = .true. ,
tprnfor = .true. ,
nstep = 55 ,
etot_conv_thr = 1.0E-5 ,
forc_conv_thr = 1.0D-4 ,
iprint = 1 ,
max_seconds = 6000 ,
dt = 150 ,
/
&system
ibrav =4, 
celldm(1) =8.98943, 
celldm(3) = 2.73029,
nat=10, ntyp= 2,
ecutwfc =25.0
/
&electrons
conv_thr = 1.0d-8
mixing_beta = 0.7
/
&IONS
/
&CELL
cell_dynamics = 'damp-w' ,
press = 0.00 ,
wmass = 0.00700000 , 
/
ATOMIC_SPECIES
Al  26.98  Al.vbc.UPF
O   15.999 O.pw91-van_ak.UPF
ATOMIC_POSITIONS {crystal}
Al 0.3554 0.3554 0.3554
Al 0.1480 0.1480 0.1480
Al 0.6480 0.6480 0.6480 
Al 0.8519 0.8519 0.8519 
O 0.2500 0.9437 0.5562
O 0.9437 0.5562 0.2500
O 0.5562 0.2500 0.9437 
O 0.7500 0.0562 0.4437 
O 0.4437 0.7500 0.0562 
O 0.0562 0.4437 0.7500 
K_POINTS {automatic}
4 4 4 1 1 1
EOF
 
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=======================================================
Fatma Litimein 
Computational Materials Science Laboratory,
Physics Department, University of Sidi Bel Abbes
Sidi Bel Abbes, 22000 - Algeria
Tel:+213 48-54-95-46 Fax:+213 48-54-19-28 flitimein at yahoo.fr
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