[Pw_forum] Phonon of ScN

[Sohail Ahmad]

Dear All,I am trying to calculate phonon frequencies of ScN, 
but i am not getting as reported by Prof Umesh Waghmare groupJournal of Applied Physics, 107, 03715 (2010)Electronic structure, phonons and thermal properties of ScN, ZrN and HfN
I am not getting any frequency around 600 cm-1.Pls check and suggest any mistakes-----------------------------------------------------------------------------
Output (and input )of my calculation at Gamma for ScN is as follows

q = (    0.000000000   0.000000000   0.000000000 ) 

 **************************************************************************
     freq (    1) =       0.073720 [THz] =       2.459027 [cm-1]
     freq (    2) =       0.312948 [THz] =      10.438836 [cm-1]
     freq (    3) =       0.312948 [THz] =      10.438836 [cm-1]
     freq (    4) =      10.407119 [THz] =     347.144126 [cm-1]
     freq (    5) =      10.472361 [THz] =     349.320372 [cm-1]
     freq (    6) =      10.472361 [THz] =     349.320372 [cm-1]
 **************************************************************************

     Mode symmetry, C_3v (3m)   point group:

     freq (  1 -  1) =          2.5  [cm-1]   --> A_1  L_1        I+R
     freq (  2 -  3) =         10.4  [cm-1]   --> E    L_3        I+R
     freq (  4 -  4) =        347.1  [cm-1]   --> A_1  L_1        I+R
     freq (  5 -  6) =        349.3  [cm-1]   --> E    L_3        I+R
 --------------------------------------------------------------------------------------
&SYSTEM
   ibrav=2,
   a=4.501,
   nat=2, ntyp=2,
   ecutwfc = 250, ecutrho = 1000,
   nbnd=15,
   occupations = 'smearing', smearing = 'gaussian', degauss = 0.001,
   nspin = 2,
   starting_magnetization(1)=0.1d0,
  /
 &ELECTRONS
    conv_thr =  1.0d-9,
    mixing_beta = 0.3,
 /
 ATOMIC_SPECIES
  Sc 44.956   Sc.pw91-nsp-van.UPF
  N  14.007   N.pw91-van_ak.UPF
 ATOMIC_POSITIONS {angstrom}
 Sc  -0.044377705  -0.044377705  -0.044377705
 N    2.294877705   2.294877705   2.294877705
 K_POINTS automatic
12 12 12 1 1 1
-------------------------------------------------------------------- &inputph
 tr2_ph = 1.0d-16,
 amass(1) = 44.956,
 amass(2) = 14.007,
 prefix = 'ScN',
 !epsil=.true.,  ! set this to true for polar semiconductors !
 outdir = '/scratch/ScN-scf-30591'
 fildyn = 'ScN.dynG',
/
0.0  0.0  0.0

--------------------------------------------------------------------- 
Dr. Sohail AhmadKing Khalid UniversityAbha, Saudi Arabia--------------------------------------------------------------------
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