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["PRASENJIT GHOSH" <prasenjit@jncasr.ac.in>]

I am using 'anaddb' utility (version 4.1.4) to obtain the phonon
dispersion for Te.
In the input file for anaddb, if I use "eivec=4" flag, the phonon modes
change considerably compared to a calculation done without using
"eivec=4".
I feel that using "eivec=4" shouldnot change the values of the phonon
frequencies. Can any one please help me out with the above mentioned
problem?

Following is my input file is as follows:

 !Input file for the ifc code. Analysis of the Al DDB

!Flags
 ifcflag   1     ! Interatomic force constant flag

!Effective charges
     asr   1     ! Acoustic Sum Rule. 1 => imposed asymetrically

 enunit   2
 eivec  4
!Interatomic force constant info
  dipdip  0      ! Dipole-dipole interaction treatment
  ifcana  1      ! Analysis of the IFCs
  ifcout 20      ! Number of IFC's written in the output, per atom
  natifc  3      ! Number of atoms in the cell for which ifc's are analysed
   atifc  1 1 1      ! List of atoms

!Wavevector grid number 1 (coarse grid, from DDB)
  brav    4      ! Bravais Lattice : 1-S.C., 2-F.C., 3-B.C., 4-Hex.)
  ngqpt   1  1  5   ! Monkhorst-Pack indices
  nqshft  1         ! number of q-points in repeated basic q-cell
  q1shft  0.0  0.0  0.0

!Wavevector list number 1 (Reduced coordinates and normalization factor)

  nph1l    3      ! number of phonons in list 1
  qph1l   0.0  0.0  0.0    1.0   ! (Gamma point)
          0.0  0.0  0.2    1.0
          0.0  0.0  0.4    1.0

With regards,
Prasenjit.

PRASENJIT GHOSH,
Ph. D STUDENT,
THEORETICAL SCIENCES UNIT,
JAWAHARLAL NEHRU CENTRE,
JAKKUR P. O.,
BANGALORE - 560064,
INDIA.

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