[QE-users] 'q not allowed' error in phonon dispersion calculations

[jibiaoli]

Dear all, I'm trying to calculate the phonon dispersion for  Selenium as suggested in the example files. I ran successfully
the ph.x code for the input 2. However, when I was trying to get the force constants in real space by using the q2r.x code, I keep getting the following error:

      MPI processes distributed on     1 nodes
     reading grid info from file Se_bcd.disp.dyn0    
  reading force constants from file Se_bcd.disp.dyn1
  Dielectric Tensor not found
  nqs=            1
 q=   0.00000000  0.00000000  0.00000000
  reading force constants from file Se_bcd.disp.dyn2
  nqs=            2
 q=   0.00000509  0.14390743  0.00000000
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     Error in routine init (1):
     q not allowed
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     stopping ...
 Can anyone help me? What's wrong with my inputs?


Best
Jibiao Li
Yangtze Normal University, China


input 1: Se_bcd.vc.inp
 &CONTROL
                 calculation = 'vc-relax' ,
                restart_mode = 'from_scratch' ,
                      outdir = './' ,
                  pseudo_dir = '/home/jibiaoli/pseudo/' ,
                       nstep = 100,
                      prefix = 'Se_bcd' ,
                     disk_io = 'high' ,
 /
 &SYSTEM
                       ibrav = 8,
                   celldm(1) = 8.137636,
                   celldm(2) = 0.7923,
                   celldm(3) = 3.1,
                         nat = 3,
                        ntyp = 1,
                     ecutwfc = 41 ,
                     ecutrho = 410 ,
                 occupations = 'smearing' ,
                     degauss = 0.05D0 ,
                    smearing = 'methfessel-paxton' ,
                    vdw_corr = 'grimme-d2' ,
 /
 &ELECTRONS
                    conv_thr = 1d-8 ,
                 mixing_beta = 0.3D0 ,
             diagonalization = 'david' ,
 /
 &IONS
                ion_dynamics = 'bfgs' ,
 /
 &CELL
               cell_dynamics = 'bfgs' ,
                 cell_dofree = '2Dxy' ,
 /
ATOMIC_SPECIES
   Se   78.96100  Se.pbe-van.UPF 
ATOMIC_POSITIONS (angstrom)
Se       1.473000000   1.700088386   0.866948117
Se       0.000000000   0.000000000   0.000000000    0   0   0
Se       2.840000000   1.700051575  -0.870383743
K_POINTS automatic 
  9 9 1   0 0 0 


input 2: Se.ph.disp.inp
Phonon dispersions for Se
 &inputph
  tr2_ph=1.0d-14,
  prefix='Se_bcd',
  outdir='./',
  alpha_mix(1)=0.15,
  fildyn='Se_bcd.disp.dyn',
  ldisp=.true.,
  nq1=8, nq2=8, nq3=1,
 /


input 3: q2r.in
 &input
  zasr='simple',  fildyn='Se_bcd.disp.dyn', flfrc='Se881.fc', loto_2d=.true.,
 /


input 4: matdyn.in
 &input
    asr='simple', 
    flfrc='Se881.fc', flfrq='Se.freq', q_in_band_form=.true., loto_2d=.true.,
 /
 4
  0.00000000 0.00000000 0.0   40
  0.33333333 0.57735027 0.0   20
  0.00000000 0.57735027 0.0   30
  0.00000000 0.00000000 0.0   1


input 5: plotband.in
Se.freq
0 1650
freq.disp.plot
freq.disp.ps
0.0
50.0 0.0
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20181226/5886174b/attachment.html>