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Experimental data for O2 (Oxygen diatomic)

22 02 02 11 45
Other names
Dioxygen; Molecular oxygen; Oxygen; Oxygen molecule; Oxygen-16;
INChI INChIKey SMILES IUPAC name
InChI=1S/O2/c1-2 MYMOFIZGZYHOMD-UHFFFAOYSA-N O=O Dioxygen
State Conformation
3Σg D*H
Enthalpy of formation (Hfg), Entropy, Integrated heat capacity (0 K to 298.15 K) (HH), Heat Capacity (Cp)
Property Value Uncertainty units Reference Comment
Hfg(298.15K) enthalpy of formation 0.00 0.00 kJ mol-1 CODATA
Hfg(0K) enthalpy of formation 0.00 0.00 kJ mol-1 CODATA
Entropy (298.15K) entropy 205.15 0.00 J K-1 mol-1 CODATA
Integrated Heat Capacity (0 to 298.15K) integrated heat capacity 8.68 0.00 kJ mol-1 CODATA
Heat Capacity (298.15K) heat capacity 29.38   J K-1 mol-1 Gurvich
Information can also be found for this species in the NIST Chemistry Webbook
Vibrational levels (cm-1) vibrations
Mode Number Symmetry Frequency Intensity Comment Description
Fundamental(cm-1) Harmonic(cm-1) Reference (km mol-1) unc. Reference
1 Σg 1556 1580 1979HUB/HER      

Detailed diatomic data
ωe ωexe ωeye Be αe ZPE reference
1580.161 11.95127 0.0458489 1.44562 0.0159305 787.3797 2007Iri:389

vibrational zero-point energy: 778.2 cm-1 (from fundamental vibrations)
Calculated vibrational frequencies for O2 (Oxygen diatomic).
More spectroscopic constants are available at the NIST Physics Laboratory website:
http://physics.nist.gov/PhysRefData/MolSpec/Diatomic/Html/Tables/O2.html
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment
  1.43768   1979HUB/HER

Calculated rotational constants for O2 (Oxygen diatomic).
Product of moments of inertia moments of inertia
11.72561amu Å2   1.947113E-39gm cm2
Geometric Data
picture of Oxygen diatomic

Point Group D∞h


Internal coordinates
distances (r) in Å, angles (a) in degrees, dihedrals (d) in degrees
Description Value unc. Connectivity Reference Comment
Atom 1 Atom 2 Atom 3 Atom 4
rOO 1.208   1 2 1979HUB/HER re

Cartesians
Atom x (Å) y (Å) z (Å)
O1 0.0000 0.0000 0.0000
O2 0.0000 0.0000 1.2075

Atom - Atom Distances bond lengths
Distances in Å
  O1 O2
O1   1.2075
O2 1.2075  

Calculated geometries for O2 (Oxygen diatomic).

Bond descriptions


Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
O=O 1

Connectivity
Atom 1 Atom 2
O1 O2
Electronic energy levels (cm-1)
Energy (cm-1) Degeneracy reference description
0 3 1979HUB/HER 3Σg
7918.1 2 1979HUB/HER 1Δg
13195.1 1 1979HUB/HER 1Σg+
33057.3 1 1979HUB/HER 1Σu-

Ionization Energies (eV)
Ionization Energy I.E. unc. vertical I.E. v.I.E. unc. reference
12.070 0.000 12.300   webbook

Electron Affinity (eV)
Electron Affinity unc. reference
0.451 0.007 webbook

Proton Affinity (kJ mol-1)
Proton Affinity unc. Product reference comment
421.0   HO2+ webbook  
Dipole, Quadrupole and Polarizability
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State Config State description Conf description Exp. min. Dipole (Debye) Reference comment Point Group Components
x y z total dipole quadrupole