[Pw_forum] Problem with vc-relax calculation - pwscf 5.1.2

[Elham]

I first relax system and then do vc-relax calculation but show this in the
force and strange for me?

Because of the before do vc-relax calculation I didn't show this behavior
in this force?

Total force of system converged to   0.000335 but last scf  total force is
different and larger than this force (0.004711). in the most calculation
this two amount must be same.


all of total force in vc-relax calculation:

     Total force =     0.004513     Total SCF correction =     0.000180
     Total force =     0.018979     Total SCF correction =     0.000142
     Total force =     0.017385     Total SCF correction =     0.000143
     Total force =     0.039273     Total SCF correction =     0.000107
     Total force =     0.013076     Total SCF correction =     0.000222
     Total force =     0.006658     Total SCF correction =     0.000104
     Total force =     0.005537     Total SCF correction =     0.000050
     Total force =     0.005065     Total SCF correction =     0.000046
     Total force =     0.002880     Total SCF correction =     0.000044
     Total force =     0.000900     Total SCF correction =     0.000005
     Total force =     0.000570     Total SCF correction =     0.000011
     Total force =     0.000335     Total SCF correction =     0.000015
     Total force =     0.004711     Total SCF correction =     0.000023

my input:

&CONTROL
  calculation  = "vc-relax",
  prefix       = "221-50GrporFe",
  pseudo_dir = ./pseudo',
  outdir='./tmp3',
  disk_io='none' ,
  tprnfor=.TRUE. ,
  tstress=.TRUE. ,
  forc_conv_thr=1.0D-4 ,
  etot_conv_thr=1.0D-5,
/
&SYSTEM
  ibrav     = 8,
  celldm(1) =23.255385645,
  celldm(2) =1.0392304835091129925263003159134,
  celldm(3) =1.3001554254551417531019473809222,
  nat       = 59,
  ntyp      = 3,
  ecutwfc   = 50.0,
  ecutrho   = 300.0,
  occupations='smearing',
  smearing='gaussian',
  degauss=0.01,
  nspin =2 ,
  starting_magnetization(1)=  0.0 ,
  starting_magnetization(2)=  0.5 ,
  starting_magnetization(3)=  0.0 ,
  vdw_corr='DFT-D'
/
&ELECTRONS
  conv_thr    = 1.D-8,
  mixing_beta = 0.7D0,
/
&IONS
  ion_dynamics = 'bfgs'
/
&CELL
cell_factor=1.2 ,
cell_dofree='xy'
/
ATOMIC_SPECIES
C  12.0107     C.pbe-n-kjpaw_psl.0.1.UPF
Fe 55.8450     Fe.pbe-spn-kjpaw_psl.0.2.1.UPF
N  14.0067     N.pbe-n-kjpaw_psl.0.1.UPF
ATOMIC_POSITIONS (angstrom)

K_POINTS  {automatic}
2 2 1 0 0 0
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