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)

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)
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
193251.2	amu3Å6		8.84891704982812E-115	gm3 cm6

Geometric Data

Point Group C_2h

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

Cartesians

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
Distances in Å

	N1	N2	O3	O4
N1		2.2360	1.1610	2.6858
N2	2.2360		2.6858	1.1610
O3	1.1610	2.6858		2.6232
O4	2.6858	1.1610	2.6232

Calculated geometries for ONNO (NO dimer).

Experimental Bond Angles (degrees) from cartesians

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
For a molecule with C_2h symmetry there is no dipole.
Electric quadrupole moment
Calculated electric quadrupole moments for ONNO (NO dimer).

References
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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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