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Dear all,

I am trying to caluculate Phonon dispersion curve of bulk cubic boron nitride,
and got a differet result compared with the paper (PRB. v62 p8003).

The gamma point of my result is 

Phonon frequencies in cm-1:
-  1.030878E+02  1.030879E+02  1.030879E+02  6.849660E+02  6.849660E+02
-  6.849660E+02  6.849660E+02  6.849660E+02  6.849661E+02  8.767864E+02
-  8.767864E+02  8.767864E+02  8.767865E+02  8.767865E+02  8.767865E+02
-  9.680494E+02  9.680494E+02  9.680494E+02  1.025045E+03  1.025045E+03
-  1.025045E+03  1.131268E+03  1.131268E+03  1.131268E+03

But of paper (PRB. v62 p8003) is 

TO phonon frequency : 1061 cm-1
LO phonon frequency : 1280 cm-1

Anyone can give me some comments to improve my input files.

-------------------Here is my input files------------------------------------

 ndtset 3

#Ground state calculation
  kptopt1   1
  tolvrs1   1.0d-18
    iscf1   5
  prtden1   1

#Response Function calculation : d/dk
  rfelfd2   2
   rfdir2   1 1 1

    nqpt2   1
     qpt2   0.0 0.0 0.0

  getwfk2   -1
  kptopt2   2
    iscf2  -3
  tolwfr2   1.0d-22

#Response Function calculation : electric field perturbation and phonons
  rfphon3   1
 rfatpol3   1 8
  rfelfd3   3
   rfdir3   1 1 1
    nqpt3   1
     qpt3   0.0 0.0 0.0
  getwfk3   -2
  getddk3   -1
  kptopt3   2
  tolvrs3   1.0d-8
    iscf3   5

#Common data
 ngkpt  4 4 4
 ecut 32
 acell 6.834 6.834 6.834
 chkprim 0
 ixc    1
 natom  8
 nstep 80
 ntypat  2
 diemac 12.0
 angdeg 90 90 90
 typat  1 1 1 1 2 2 2 2
 znucl 5 7
 xred
       0.000000   0.000000   0.000000
       0.000000   0.500000   0.500000
       0.500000   0.000000   0.500000
       0.500000   0.500000   0.000000
       0.250000   0.250000   0.250000
      -0.250000  -0.250000   0.250000
      -0.250000   0.250000  -0.250000
       0.250000  -0.250000  -0.250000