[Pw_forum] Convergence NOT achieved for Sr2MnMoO6 using PAW pp

[Shuai]

Dear User:

I am doing the SCF calculation of Sr2MnMoO6 using PAW Potentials but it 
cannot converged.

I checked different Ecut (30Ry, 40Ry or 50Ry), mixing mode (TF or 
plain), diagonalization (david or cg) and mixing_beta (0.3, 0.7), but it 
always not converged.

The SCF input is:

  &control
   calculation   = 'scf'
   prefix           = 'Sr2MnMoO6'
   restart_mode  = 'from_scratch'
   pseudo_dir    = '/'
   outdir           = '/'
  /
  &system
   ibrav            = 1
   celldm(1)     = 15.27295
   nat               = 40
   ntyp             = 4
   ecutwfc        = 50
   ecutrho        = 600
   occupations   = 'smearing'
   smearing      = 'mp'
   degauss        = 0.01
   lda_plus_u     = .true.
   Hubbard_U(2)  = 4.0
  /
  &electrons
   conv_thr         = 1e-8
   mixing_mode   = 'TF'
   mixing_beta   = 0.7
   diagonalization = 'david'
  /
ATOMIC_SPECIES
   Sr    87.620   Sr.pbe-spn-kjpaw_psl.1.0.0.UPF
   Mn   54.938   Mn.pbe-spn-kjpaw_psl.1.0.0.UPF
   Mo   95.960   Mo.pbe-spn-kjpaw_psl.1.0.0.UPF
   O     15.999   O.pbe-n-kjpaw_psl.1.0.0.UPF
ATOMIC_POSITIONS (crystal)
   Sr    0.0000   0.0000   0.0000
   Sr    0.5000   0.0000   0.0000
   Sr    0.0000   0.5000   0.0000
   Sr    0.5000   0.5000   0.0000
   Sr    0.0000   0.0000   0.5000
   Sr    0.5000   0.0000   0.5000
   Sr    0.0000   0.5000   0.5000
   Sr    0.5000   0.5000   0.5000
   Mn   0.2500   0.2500   0.2500
   Mo   0.7500   0.2500   0.2500
   Mo   0.2500   0.7500   0.2500
   Mn   0.7500   0.7500   0.2500
   Mo   0.2500   0.2500   0.7500
   Mn   0.7500   0.2500   0.7500
   Mn   0.2500   0.7500   0.7500
   Mo   0.7500   0.7500   0.7500
   O     0.2500  -0.0140   0.2500
   O    -0.0140   0.2500   0.2500
   O     0.2500   0.2500  -0.0140
   O     0.7500   0.0140   0.2500
   O     0.5140   0.2500   0.2500
   O     0.7500   0.2500   0.0140
   O     0.2500   0.5140   0.2500
   O     0.0140   0.7500   0.2500
   O     0.2500   0.7500   0.0140
   O     0.7500   0.4860   0.2500
   O     0.4860   0.7500   0.2500
   O     0.7500   0.7500  -0.0140
   O     0.2500   0.0140   0.7500
   O     0.0140   0.2500   0.7500
   O     0.2500   0.2500   0.5140
   O     0.7500  -0.0140   0.7500
   O     0.4860   0.2500   0.7500
   O     0.7500   0.2500   0.4860
   O     0.2500   0.4860   0.7500
   O    -0.0140   0.7500   0.7500
   O     0.2500   0.7500   0.4860
   O     0.7500   0.5140   0.7500
   O     0.5140   0.7500   0.7500
   O     0.7500   0.7500   0.5140
K_POINTS (automatic)
   4 4 4 1 1 1

Thanks in advance for your suggestions.

Best regards,

Shuai Zhao

-- 
PhD candidate
Graduate School of Life Science and Systems Engineering
Kyushu Institute of Technology, Japan