CO vibration: Difference between revisions
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== Task == | == Task == | ||
Calculation of the vibrational frequencies of a CO molecule. | |||
== Input == | == Input == | ||
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*The selected degrees of freedom are displaced once in the direction <math>\hat{x}</math> and once in <math>-\hat{x}</math> by 0.002 <math>\AA</math> ({{TAG|POTIM}}). | *The selected degrees of freedom are displaced once in the direction <math>\hat{x}</math> and once in <math>-\hat{x}</math> by 0.002 <math>\AA</math> ({{TAG|POTIM}}). | ||
*In the present case this makes 4 displacements plus the equilibrium positions (i.e. a total of five ionic configurations). | |||
=== {{TAG|OUTCAR}} === | |||
At the end of the {{TAG|OUTCAR}} file the following output should be obtained: | |||
SECOND DERIVATIVES (NOT SYMMETRIZED) | |||
------------------------------------ | |||
1Z 2Z | |||
1Z -114.737304 114.737304 | |||
2Z 114.458316 -114.458316 | |||
Eigenvectors and eigenvalues of the dynamical matrix | |||
---------------------------------------------------- | |||
1 f = 63.887522 THz 401.417139 2PiTHz 2131.058277 cm-1 264.217647 meV | |||
X Y Z dx dy dz | |||
0.000000 0.000000 0.000000 0 0 -0.655280 | |||
0.000000 0.000000 1.143000 0 0 0.755386 | |||
2 f/i= 0.038494 THz 0.241864 2PiTHz 1.284016 cm-1 0.159198 meV | |||
X Y Z dx dy dz | |||
0.000000 0.000000 0.000000 0 0 -0.755386 | |||
0.000000 0.000000 1.143000 0 0 -0.655280 | |||
== Download == | == Download == | ||
Revision as of 09:11, 28 April 2017
Overview > O atom > O atom spinpolarized > O atom spinpolarized low symmetry > O dimer > CO > CO vibration > CO partial DOS > H2O >
H2O vibration > H2O molecular dynamics > Further things to try > List of tutorials
Task
Calculation of the vibrational frequencies of a CO molecule.
Input
POSCAR
CO molecule in a box 1.0 ! universal scaling parameters 8.0 0.0 0.0 ! lattice vector a(1) 0.0 8.0 0.0 ! lattice vector a(2) 0.0 0.0 8.0 ! lattice vector a(3) 1 1 ! number of atoms for each species sel ! selective degrees of freedom are changed cart ! positions in cartesian coordinates 0 0 0 F F T ! first atom 0 0 1.143 F F T ! second atom
Alternatively, try to fix one of the atoms completely.
INCAR
SYSTEM = CO molecule in a box ISMEAR = 0 ! Gaussian smearing IBRION = 5 ! use the conjugate gradient algorithm NFREE = 2 ! central differences POTIM = 0.02 ! 0.02 A stepwidth NSW = 1 ! ionic steps > 0
KPOINTS
Gamma-point only 0 Monkhorst Pack 1 1 1 0 0 0
Calculation
- The selected degrees of freedom are displaced once in the direction and once in by 0.002 (POTIM).
- In the present case this makes 4 displacements plus the equilibrium positions (i.e. a total of five ionic configurations).
OUTCAR
At the end of the OUTCAR file the following output should be obtained:
SECOND DERIVATIVES (NOT SYMMETRIZED)
------------------------------------
1Z 2Z
1Z -114.737304 114.737304
2Z 114.458316 -114.458316
Eigenvectors and eigenvalues of the dynamical matrix
----------------------------------------------------
1 f = 63.887522 THz 401.417139 2PiTHz 2131.058277 cm-1 264.217647 meV
X Y Z dx dy dz
0.000000 0.000000 0.000000 0 0 -0.655280
0.000000 0.000000 1.143000 0 0 0.755386
2 f/i= 0.038494 THz 0.241864 2PiTHz 1.284016 cm-1 0.159198 meV
X Y Z dx dy dz
0.000000 0.000000 0.000000 0 0 -0.755386
0.000000 0.000000 1.143000 0 0 -0.655280
Download
To the list of examples or to the main page