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 ONNO (NO dimer)

State Conformation
1Ag trans C2H
Enthalpy of formation (Hfg), Entropy, Integrated heat capacity (0 K to 298.15 K) (HH), Heat Capacity (Cp)
Property Value Uncertainty units Reference Comment
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

Calculated vibrational frequencies for ONNO (NO dimer).
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment
0.86159 0.18728 0.15363 1983Kuc:80

Calculated rotational constants for ONNO (NO dimer).

Product of moments of inertia moments of inertia
193251.2amu3Å6   8.84891704982812E-115gm3 cm6
Geometric Data
picture of NO dimer

Point Group C2h

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
rNO 1.161 0.004 1 3 1983Kuc:80
rNN 2.236 0.001 1 2 1983Kuc:80
aNNO 99.6 0.2 1 2 4 1983Kuc:80


Atom x (Å) y (Å) z (Å)
N1 0.0000 1.1180 0.6105
N2 0.0000 -1.1180 0.6105
O3 0.0000 1.3116 -0.5342
O4 0.0000 -1.3116 -0.5342

Atom - Atom Distances bond lengths
Distances in Å

  N1 N2 O3 O4
N1   2.23601.16102.6858
N2 2.2360   2.68581.1610
O3 1.16102.6858   2.6232
O4 2.68581.16102.6232  

Calculated geometries for ONNO (NO dimer).

Experimental Bond Angles (degrees) from cartesians bond angles

atom1 atom2 atom3 angle         atom1 atom2 atom3 angle
N1 N2 O4 99.600 N2 N1 O3 99.600

Bond descriptions

Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
N-N 1
N=O 2
Electronic energy levels (cm-1)
Energy (cm-1) Degeneracy reference description
0 1   1Ag
Dipole, Quadrupole and Polarizability
Electric dipole moment dipole
For a molecule with C2h symmetry there is no dipole.
Electric quadrupole moment quadrupole
Calculated electric quadrupole moments for ONNO (NO dimer).

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squib reference DOI
1983Kuc:80 SG Kuckolich "Structure and Quadrupole Coupling Measurements of the NO Dimer" J. Molecular Spectroscopy 98, 80-86 (1983) 10.1016/0022-2852(83)90204-7

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