[Pw_forum] A long relaxation

[Pedro Augusto F. P. Moreira]

  Dear all,

  I am doing a relaxation which is consuming a very long time. My input 
is below, but I think it is OK, because there is nothing wrong with my 
output and the system energies are decreasing .
  However, I have noted that the total forces and the forces acting on 
each atoms have oscillated a lot. I summarized below the total forces, 
which are showed in the end of each SC calculation.
  Is it right? Or could the program find a local minimum and cannot get 
out of it (or anything similar)?

  Thanks a lot,

  Pedro

####Total forces#####
      Total force =     0.162129     Total SCF correction =     0.000046
      Total force =     0.131410     Total SCF correction =     0.039799
      Total force =     0.199885     Total SCF correction =     0.004809
      Total force =     0.254130     Total SCF correction =     0.004143
      Total force =     0.285538     Total SCF correction =     0.003092
      Total force =     0.339246     Total SCF correction =     0.001453
      Total force =     0.419218     Total SCF correction =     0.000630
      Total force =     0.509140     Total SCF correction =     0.000243
      Total force =     0.593476     Total SCF correction =     0.000133
      Total force =     0.534968     Total SCF correction =     0.000206
      Total force =     0.431853     Total SCF correction =     0.004582
      Total force =     0.308932     Total SCF correction =     0.000404

#####Input########
&control
     calculation='relax',
     restart_mode='from_scratch',
     pseudo_dir = '/quantum-espresso/espresso/pseudo/',
     outdir='/quantum-espresso/espresso/tmp/',
     prefix='ap5',
     tprnfor = .true.,
     nstep = 1000,
/
&system
     ibrav = 4, celldm(1) = 17.8749, celldm(3) = 0.7241,
     nat = 42, ntyp = 4,
     ecutwfc = 52.0, ecutrho = 900.0,
/
&electrons
     electron_maxstep = 500
     mixing_beta = 0.1,
/
&ions
     ion_dynamics='bfgs',
/
ATOMIC_SPECIES
  Ca 40.0780 Ca.pz-n-vbc.UPF
  P 30.9738 P.pz-van_ak.UPF
  O 15.9994 O.pz-van_ak.UPF
  F 18.99840 F.pz-van_asa.UPF
ATOMIC_POSITIONS angstrom
.
.
.
##############################

-- 
Pedro Moreira

IFGW - Unicamp - Brazil