[Pw_forum] disconverge about phonon calculation

[潘登]

Dear All,

  I am doing a calculation of the LaFeAsO. And when I run the ph.x,
the disconverge happens in the   Representation #  3 mode #   3. I am
appraciate for any comment and suggustiong.I wonder what should I do
to avoid the disconvergence like this.
here is my inputs
ph.in
 LaFeAsO
&inputph
  amass(1)= 139.9055,
  amass(2)= 55.845,
  amass(3)= 74.9216,
  amass(4)= 15.9994,
  prefix='LaFeAsO'
  fildyn='LaFeAsO.dyn',
  tr2_ph=1.0d-8,
  lnscf=.true.,
  iverbosity=1,
  outdir='/disk2/xgwan/tmp/',
  ldisp=.true.,
  nq1=4, nq2=4, nq3=4
 /
and scf.in
 &control
     calculation = 'scf'
     restart_mode='from_scratch'
     prefix='LaFeAsO',
     pseudo_dir = '/disk2/xgwan/Quantum-Espresso/espresso-4.0.3/pseudo/',
     outdir='/disk2/xgwan/tmp/'
 /
 &system
     ibrav=6,
     celldm(1)=7.6232,
     celldm(3)=2.1676,
     nat=8,
     ntyp=4,
     ecutwfc = 40.0,
     ecutrho = 300.0,
     occupations= 'smearing'
     degauss = 0.03
     smearing = 'marzari-vanderbilt'
 /
 &electrons
     mixing_beta = 0.7
     conv_thr =  1.0d-11
 /
ATOMIC_SPECIES
 La 57.0 La.pbe-nsp-van.UPF
 Fe 28.0 Fe.pbe-sp-van.UPF
 As 33.0 As.pbe-n-van.UPF
 O  16.0 O.pbe-rrkjus.UPF
ATOMIC_POSITIONS {crystal}
La       0.250000000   0.250000000   0.139792601
La       0.750000000   0.750000000   0.860207399
Fe       0.750000000   0.250000000   0.500000000
Fe       0.250000000   0.750000000   0.500000000
As       0.250000000   0.250000000   0.636557422
As       0.750000000   0.750000000   0.363442578
O        0.750000000   0.250000000   0.000000000
O        0.250000000   0.750000000   0.000000000
K_POINTS {automatic}
  8 8 8 0 0 0


in addition all the atiomic positions have been relaxed.
cheers

Deng Pan
Nanjing University