Vibrational frequencies of CO on Ni 111 surface

From VASP Wiki

Description: compute the vibrational frequencies of CO@Ni(111) (on top).


  • INCAR
  SYSTEM= CO on Ni111 - frequencies

 general:
   ENMAX  = 400
   ISMEAR =    2  ; SIGMA = 0.2
   ALGO   = Fast
   EDIFF  = 1E-6
   MAXMIX = 60  # reuse the mixer between ionic steps, saves time

 dynamic:
   NSW=100
   IBRION = 5
   NFREE  = 2
  • KPOINTS
k-points
0
Monkhorst-Pack
9 9 1
0 0 0
  • POSCAR
Ni - (111) + CO ontop
   3.53000000000000     
     0.7071067800000000    0.0000000000000000    0.0000000000000000
    -0.3535533900000000    0.6123724000000000    0.0000000000000000
     0.0000000000000000    0.0000000000000000    5.1961523999999998
   5   1   1
Selective dynamics
Direct
  0.0000000000000000  0.0000000000000000  0.0000000000000000   F   F   F
  0.3333333300000021  0.6666666699999979  0.1111111100000031   F   F   F
  0.6666666699999979  0.3333333300000021  0.2222222199999990   F   F   F
  0.0000000000000000  0.0000000000000000  0.3330391292438326   F   F   F
  0.3333333300000021  0.6666666699999979  0.4445422014835692   F   F   F
  0.3333333300000021  0.6666666699999979  0.5402025044116211   F   F   T
  0.3333333300000021  0.6666666699999979  0.6031536532245922   F   F   T
 
  0.00000000E+00  0.00000000E+00  0.00000000E+00
  0.00000000E+00  0.00000000E+00  0.00000000E+00
  0.00000000E+00  0.00000000E+00  0.00000000E+00
  0.00000000E+00  0.00000000E+00  0.00000000E+00
  0.00000000E+00  0.00000000E+00  0.00000000E+00
  0.00000000E+00  0.00000000E+00  0.00000000E+00
  0.00000000E+00  0.00000000E+00  0.00000000E+00

Try to change the selective dynamics tag such that displacements in x and y direction are allowed as well for CO (note that the selective dynamics flags always refer to cartesian coordinates), i.e,

 0.3333333300000021  0.6666666699999979  0.5402025044116211   F   F   T
 0.3333333300000021  0.6666666699999979  0.6031536532245922   F   F   T

to

 0.3333333300000021  0.6666666699999979  0.5402025044116211   T   T   T
 0.3333333300000021  0.6666666699999979  0.6031536532245922   T   T   T


Also test whether you need to decrease EDIFF to 1E-8.

Download

COonNi111_freq.tgz


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