[Pw_forum] convergence problem in phonon calculation

[杨顶峰]

Dear All,


                I am trying the quantum espresso 5.1 to perform the phonon calculation of a compound.
firstly, i use VASP to get a better geometry calculation , then the opted model was used to carried out the self consistent calculation and phonon calculation on quantum espresso 5.1 .
my input file for the self consistent calculation  is given below:
&control
   title='sbcrse3'
   calculation = 'scf' ,
   restart_mode='from_scratch',
   wf_collect=.true.,
   prefix = 'sbcrse3',
   outdir = './',
   pseudo_dir = './',
   tstress=.true.
   tprnfor=.true.
   etot_conv_thr=1.0D-6,
   forc_conv_thr=1.0D-6,
/


&system
   ibrav = 8,
   celldm(1) = 17.721473993588537072269931508765,
   celldm(2) = 0.40987224478027270642574239356715,
   celldm(3) = 1.4354965598661794909645534975973,
   nat = 20 ,
   ntyp = 3 ,
   ecutwfc = 40,
   ecutrho = 300,
   occupations = 'fixed' ,
   nbnd = 150,
/


&electrons
   mixing_beta=0.7
   conv_thr = 1.0d-10 ,
/


ATOMIC_SPECIES
  Sb    121.7       Sb.pbe-mt_fhi.UPF
  Se    78.96       Se.pbe-mt_fhi.UPF
  Cr    51.996      Cr.pbe-mt_fhi.UPF
ATOMIC_POSITIONS crystal
Sb     0.471599996         0.250000000         0.655629992
Sb     0.528400004         0.750000000         0.344370008
Sb     0.028400004         0.750000000         0.155629992
Sb     0.971599996         0.250000000         0.844370008
.....


K_POINTS automatic
  13 13 13   0  0  0


the above calculation was running successfully. the details shows as follows:




convergence has been achieved in  76 iterations


     Forces acting on atoms (Ry/au):


     atom    1 type  1   force =     0.00330300   -0.00000173    0.01711914
     atom    2 type  1   force =    -0.00330300    0.00000173   -0.01711914
     atom    3 type  1   force =    -0.00330300    0.00000173    0.01711914
     atom    4 type  1   force =     0.00330300   -0.00000173   -0.01711914
     atom    5 type  2   force =    -0.00590819   -0.00028964    0.01684058
    ........


     Total force =     0.064539     Total SCF correction =     0.000006




     entering subroutine stress ...


          total   stress  (Ry/bohr**3)                   (kbar)     P=  -77.36
  -0.00044232   0.00000132   0.00000000        -65.07      0.19      0.00
   0.00000132  -0.00068747   0.00000000          0.19   -101.13      0.00
   0.00000000   0.00000000  -0.00044787          0.00      0.00    -65.88 


But when i begin the phonon calculation there is a problem, some tips will be show in the "out " file:
Electric Fields Calculation
     ik   1 ibnd  59 linter: root not converged  5.993E-09
     ik   1 ibnd  59 linter: root not converged  3.084E-09
     ik   2 ibnd  59 linter: root not converged  2.722E-07
     ik   2 ibnd  59 linter: root not converged  3.810E-09
     ik   2 ibnd  59 linter: root not converged  1.129E-09
     ik   3 ibnd  59 linter: root not converged  1.634E-09
     ik   3 ibnd  59 linter: root not converged  9.282E-09
     ik   3 ibnd  59 linter: root not converged  1.749E-09
     ik   4 ibnd  59 linter: root not converged  2.191E-09
     ik   4 ibnd  59 linter: root not converged  2.338E-09
     ik   4 ibnd  59 linter: root not converged  1.895E-09
     ik   5 ibnd  59 linter: root not converged  1.241E-08
     ik   5 ibnd  59 linter: root not converged  1.440E-09
     ik   5 ibnd  59 linter: root not converged  3.946E-09
     ik   6 ibnd  59 linter: root not converged  5.932E-08
     ik   6 ibnd  59 linter: root not converged  6.026E-09
     ik   6 ibnd  59 linter: root not converged  5.804E-08
     ik   7 ibnd  59 linter: root not converged  6.012E-09
     ik   7 ibnd  59 linter: root not converged  1.088E-09
     ik   7 ibnd  59 linter: root not converged  1.407E-08
     ik   8 ibnd  59 linter: root not converged  1.962E-09
................
the calculation is still on progress, i really don`t know how to conquer the problem as a new beginner, please help me, Thanks a lot!
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