My Community

Hi all vasp users,
Recently I tried to calculate the binding energy of molecular oxygen with vasp. in order to test the transferabilty of the pseudopotential, I looked in the vibrational frequency of oxygen dimer. So my question is : what the important parameter nedded in the incer file, and how to access to the frequency in the outcar file. This is my incar file, and poscar file:

INCAR
SYSTEM = O2 dimer in a box
ISMEAR = 0 ! Gaussian smearing
ISPIN = 2 ! spin polarized calculation
NSW = 5 ! 5 ionic steps
IBRION = 5 ! use the conjugate gradient algorithm
ENCUT = 400
VOSKOWN = 1
NFREE = 2
POTIM = 0.02
IALGO = 48

--------------------------------------------------------
POSCAR

O atom 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)
2 ! number of atoms
Sel
cart ! positions in cartesian coordinates
0 0 0 F F T ! first atom
0 0 1.22 F F T ! second atom
~
Thanks for your time and your help,
Ouarda

please have a look at the data writtein after the line
Eigenvectors and eigenvalues of the dynamical matrix
in OUTCAR

thanks for response,
I have gote this at the end of the OUTCAR file :


1 f = 49.465139 THz 310.798637 2PiTHz 1649.979438 cm-1 204.571439 meV
X Y Z dx dy dz
0.000000 0.000000 0.000000 0 0 -0.176613
0.000000 0.000000 1.220000 0 0 0.176941

2 f/i= 0.045870 THz 0.288211 2PiTHz 1.530068 cm-1 0.189704 meV
X Y Z dx dy dz
0.000000 0.000000 0.000000 0 0 -0.176941
0.000000 0.000000 1.220000 0 0 -0.176613
-------------------------
my question is where is the frequency ( for oxygen the experimental value is 1580 (1/cm))

I think it should be 1649.979438 cm-1

why do you assure the result?