[Pw_forum] ph.x

[shiva mokhavat]

dear users
I want to calculate phonon properties of cinnabar hexagonal structure of
HgTe, but when I reun ph.x some of the frequencies are negative. why this
happen? could anyone help me in this?
Shahid Chamran University of Ahwaz

the scf file:
&CONTROL
    calculation='scf'
    restart_mode='from_scratch',
    outdir='/home/1/tmp/',
    prefix='ph',
    pseudo_dir = '/home/1/pseudo/',
      tstress  = .TRUE.,
      tprnfor  = .TRUE.,
     verbosity = 'high',
 /
 &SYSTEM
            ibrav = 4,
        celldm(1) = 8.410,
        celldm(3) = 2.276,
              nat = 6
             ntyp = 2,
            nspin = 1,
          ecutwfc = 40,
          ecutrho = 160,
      occupations = 'smearing',
          degauss = 0.01,
         smearing ='mp',
 /

&ELECTRONS
     conv_thr=1.D-7,
     mixing_beta=0.7,
/
 &IONS
 /
ATOMIC_SPECIES
  Hg    200.59   80-Hg.GGA.fhi.UPF
  Te    127.6    52-Te.GGA.fhi.UPF
ATOMIC_POSITIONS (crystal)
Hg       0.641   0.000   0.333
Hg       0.000   0.641   0.666
Hg       0.359   0.359   0.000
Te       0.562   0.000   0.833
Te       0.000   0.562   0.166
Te       0.438   0.438   0.500
K_POINTS crystal
36
   0.000000000    0.000000000    0.000000000      1.000000000
   0.066000000    0.066000000    0.000000000      1.000000000
   0.132000000    0.132000000    0.000000000      1.000000000
   0.198000000    0.198000000    0.000000000      1.000000000
   0.264000000    0.264000000    0.000000000      1.000000000
   0.330000000    0.330000000    0.000000000      1.000000000
   0.364000000    0.264000000    0.000000000      1.000000000
   0.398000000    0.198000000    0.000000000      1.000000000
   0.432000000    0.132000000    0.000000000      1.000000000
   0.466000000    0.066000000    0.000000000      1.000000000
   0.500000000    0.000000000    0.000000000      1.000000000
   0.400000000    0.000000000    0.000000000      1.000000000
   0.300000000    0.000000000    0.000000000      1.000000000
   0.200000000    0.000000000    0.000000000      1.000000000
   0.100000000    0.000000000    0.000000000      1.000000000
   0.000000000    0.000000000    0.000000000      1.000000000
   0.000000000    0.000000000    0.100000000      1.000000000
   0.000000000    0.000000000    0.200000000      1.000000000
   0.000000000    0.000000000    0.300000000      1.000000000
   0.000000000    0.000000000    0.400000000      1.000000000
   0.000000000    0.000000000    0.500000000      1.000000000
   0.000000000    0.100000000    0.500000000      1.000000000
   0.000000000    0.200000000    0.500000000      1.000000000
   0.000000000    0.300000000    0.500000000      1.000000000
   0.000000000    0.400000000    0.500000000      1.000000000
   0.000000000    0.500000000    0.500000000      1.000000000
   0.066000000    0.466000000    0.500000000      1.000000000
   0.132000000    0.432000000    0.500000000      1.000000000
   0.198000000    0.398000000    0.500000000      1.000000000
   0.264000000    0.364000000    0.500000000      1.000000000
   0.330000000    0.330000000    0.500000000      1.000000000
   0.264000000    0.264000000    0.500000000      1.000000000
   0.198000000    0.198000000    0.500000000      1.000000000
   0.132000000    0.132000000    0.500000000      1.000000000
   0.066000000    0.066000000    0.500000000      1.000000000
   0.000000000    0.000000000    0.500000000      1.000000000
   0.000000000    0.000000000    0.400000000      1.000000000
   0.000000000    0.000000000    0.300000000      1.000000000
   0.000000000    0.000000000    0.200000000      1.000000000
   0.000000000    0.000000000    0.100000000      1.000000000
   0.000000000    0.000000000    0.000000000      1.000000000

the ph file:
phonons of HgTe
 &inputph
  tr2_ph=1.0d-12,
  ldisp=.true.,
  nq1=3, nq2=3 ,nq3=2
  amass(1)=200.59,
  amass(2)=127.6,
    outdir='/home/1/tmp/',
    prefix='ph',
  fildyn='cinn.dyn',
 /
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