Vibrational frequencies of CO on Ni 111 surface: Difference between revisions
Line 67: | Line 67: | ||
== Calculation == | == Calculation == | ||
Try to change the selective dynamics tag such that displacements | *Finite differences give the following additional output in the {{TAG|OUTCAR}} fiel for frequency calculations: | ||
Finite differences progress: | |||
Degree of freedom: 1/ 2 | |||
Displacement: 1/ 2 | |||
Total: 1/ 4 | |||
*After the first calculation for the equilibrium geometry, {{TAG|NFREE}} displacements (<math>\pm</math>{{TAG|POTIM}}) are performed for each degree of freedom. From these displacements the dynamical matrix is set up and diagonalized. | |||
*At the end of the {{TAG|OUTCAR}} file the following are listed: | |||
**Forces. | |||
**The dynamical matrix and finally. | |||
**The eigenfrequencies. | |||
**Eigenvectors (first normalized and then mass-weighted). | |||
*Try to change the selective dynamics tag such that displacements | |||
in x and y direction are allowed as well for CO (note that | in x and y direction are allowed as well for CO (note that | ||
the selective dynamics flags always refer to cartesian coordinates), | the selective dynamics flags always refer to cartesian coordinates), |
Revision as of 10:23, 17 May 2017
Overview > Ni 100 surface relaxation > Ni 100 surface DOS > Ni 100 surface bandstructure > Ni 111 surface relaxation > CO on Ni 111 surface > Ni 111 surface high precision > partial DOS of CO on Ni 111 surface > vibrational frequencies of CO on Ni 111 surface > STM of graphite > STM of graphene > collective jumps of a Pt adatom on fcc-Pt (001): Nudged Elastic Band Calculation > List of tutorials
Task
Calculation of the vibrational frequencies of CO@Ni(111) (on top).
Input
POSCAR
Ni - (111) + CO on-top 3.53000000000000 0.7071067800000000 0.0000000000000000 0.0000000000000000 -0.3535533900000000 0.6123724000000000 0.0000000000000000 0.0000000000000000 0.0000000000000000 5.1961523999999999 Ni C O 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 0.3326227833039623 F F F 0.3333333300000021 0.6666666699999979 0.4445699380869117 F F F 0.3333333300000021 0.6666666699999979 0.5403264650180125 F F T 0.3333333300000021 0.6666666699999979 0.6032949698060487 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
- Frequencie only for CO molecule and z-direction (z- and (x,y) are independent).
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
- Small termination criterion (EDIFF).
- Automatic frequency calculation (displacement 0.04 ).
- Reuse of the mixer between ionic steps (MAXMIX) to save time.
KPOINTS
k-points 0 Monkhorst-Pack 9 9 1 0 0 0
Calculation
- Finite differences give the following additional output in the OUTCAR fiel for frequency calculations:
Finite differences progress: Degree of freedom: 1/ 2 Displacement: 1/ 2 Total: 1/ 4
- After the first calculation for the equilibrium geometry, NFREE displacements (POTIM) are performed for each degree of freedom. From these displacements the dynamical matrix is set up and diagonalized.
- At the end of the OUTCAR file the following are listed:
- Forces.
- The dynamical matrix and finally.
- The eigenfrequencies.
- Eigenvectors (first normalized and then mass-weighted).
- 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 0.5403264650180125 F F T 0.3333333300000021 0.6666666699999979 0.6032949698060487 F F T
to
0.3333333300000021 0.6666666699999979 0.5403264650180125 T T T 0.3333333300000021 0.6666666699999979 0.6032949698060487 T T T
Also test whether you need to decrease EDIFF to 1E-8.
Download
To the list of examples or to the main page