[Pw_forum] bfgs vc-relax symmetry breaking

[Yaser Rehem]

Dear Javier et al.

I noticed in a previous posting that you were testing the bfgs vc- 
relax and requested the input file from a user that had seen his  
symmetry broken during relaxation.  I have also encountered this  
problem when relaxing an LiCoO2 structure.   I am using the 4.0cvs3  
release. I've pasted my input file below in case it is of use to you.

Meanwhile, per your suggestion, I'll try using the nosym flag.

Sincerely,

-Yaser Rehem
Rehem Research & Consulting

&control
     calculation = 'vc-relax'
     restart_mode='from_scratch'
     prefix='LiCoO2.lda.16.16.4'
     tstress = .true.
     tprnfor = .true.
     outdir = './output'
     pseudo_dir = '../pseudo'
  /
  &system
     ibrav=  4
     celldm(1) = 5.506963703
     celldm(3) = 5.061254424
     nat=  12
     ntyp= 3
     ecutwfc = 40
     ecutrho = 400
     ecfixed = 35
     qcutz = 35
     q2sigma = 4
     occupations = 'smearing'
     degauss = 0.03
     smearing = 'cold'
  /
  &electrons
     mixing_beta = 0.7
     conv_thr =  1.0d-8
  /
  &Ions
  	ion_dynamics = 'bfgs'
  /
  &cell
  	cell_dynamics = 'bfgs'
  /
  ATOMIC_SPECIES
   Co 58.9332  Co.pz-nd-rrkjus.UPF.txt
   Li 6.941	  Li_VDB_LDA_SEMI.UPF.txt
   O	 15.9994  O.pz-rrkjus.UPF.txt
  ATOMIC_POSITIONS
Co	0	0.021818463	-0.057337571
O	0.499999999	0.310480668	0.282051193
Li	0	0.60451232	0.785692891
O	0	0.033926343	1.287397609
Co	0.499999999	0.322831271	1.62680675
O	0	0.61186111	1.965217115
Li	0	0.035196846	2.467906226
O	0.499999999	0.322447182	2.970274878
Co	0	0.611145832	3.309737861
O	0	0.033615198	3.648617307
Li	0.499999999	0.313259151	4.157130001
O	0	0.598503748	4.663887786
  K_POINTS {automatic}
  16 16 4 0 0 0