National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 17bSeptember 2015
NIST Standard Reference Database 101
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
VIInput and output files
VIITutorials and Units
VIIILinks to other sites
XOlder CCCBDB versions
XIII Vibrations
XIVReaction data
XVEntropy data
XVIBibliographic data
XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers

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II.A.1. (XV.A.)

Listing of experimental data for NaO (sodium monoxide)

Other names
Calcined soda; Disodium monoxide; Disodium oxide; Sodium monoxide; Sodium oxide; UN 1825;
State Conformation
2Σ C*V
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 83.68 41.80 kJ mol-1 JANAF uwave spect. Yamada JCP 90, 3033, 1989.
Hfg(0K) enthalpy of formation 85.04 41.80 kJ mol-1 JANAF uwave spect. Yamada JCP 90, 3033, 1989.
Entropy (298.15K) entropy 229.13   J K-1 mol-1 JANAF
Integrated Heat Capacity (0 to 298.15K) integrated heat capacity 9.43   kJ mol-1 JANAF
Heat Capacity (298.15K) heat capacity 35.11   J K-1 mol-1 JANAF uwave spect. Yamada JCP 90, 3033, 1989. Cp from Webbook
Information can also be found for this species in the NIST Chemistry Webbook
Vibrational levels (cm-1) vibrations
Mode Number Symmetry Frequency (cm-1) Frequency Reference Intensity (km mol-1) Int. unc. Intensity Reference Comment
1 Σ 492 1979HUB/HER      

vibrational zero-point energy: 246.1 cm-1
Calculated vibrational frequencies for NaO (sodium monoxide).
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment

Calculated rotational constants for NaO (sodium monoxide).

Product of moments of inertia moments of inertia
39.69957amu Å2   6.592372E-39gm cm2
Geometric Data
picture of sodium monoxide

Point Group C∞v

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


Atom x (Å) y (Å) z (Å)
Na1 0.0000 0.0000 0.0000
O2 0.0000 0.0000 2.0515

Atom - Atom Distances bond lengths
Distances in Å

  Na1 O2
Na1   2.0515
O2 2.0515  

Calculated geometries for NaO (sodium monoxide).

Bond descriptions

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


Atom 1 Atom 2
Na1 O2
Electronic energy levels (cm-1)
Energy (cm-1) Degeneracy reference description
0 2 1989YAM/FUJ 2Σ
107.14 2 1989YAM/FUJ
2050 2 1989YAM/FUJ

Ionization Energies (eV)

Ionization Energy I.E. unc. vertical I.E. v.I.E. unc. reference
7.410       webbook
Dipole, Quadrupole and Polarizability
Electric dipole moment dipole
Calculated electric dipole moments for NaO (sodium monoxide).
Electric quadrupole moment quadrupole
Calculated electric quadrupole moments for NaO (sodium monoxide).

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squib reference DOI
1979HUB/HER Huber, K.P.; Herzberg, G., Molecular Spectra and Molecular Structure. IV. Constants of Diatomic Molecules,, Van Nostrand Reinhold Co., 1979  
1989YAM/FUJ Yamada, C.; Masaharu, F.; Hirota, E., Detection of the Nao radical by microwave spectroscopy, J. Chem. Phys. 90, 3033, 1989 10.1063/1.455905
JANAF Chase, M.W., Jr.; Davies, C.A.; Downey, J.R., Jr.; Frurip, D.J.; McDonald, R.A.; Syverud, A.N., JANAF Thermochemical Tables (Third Edition), J. Phys. Chem. Ref. Data,Suppl. 1, 1985, 14, 1.  
webbook NIST Chemistry Webbook (  

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