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)	-566.10	8.40	kJ mol-1	JANAF
Hfg(0K)	-562.47	8.40	kJ mol-1	JANAF
Entropy (298.15K)	325.43		J K-1 mol-1	JANAF
Integrated Heat Capacity (0 to 298.15K)	18.45		kJ mol-1	JANAF
Heat Capacity (298.15K)	78.77		J K-1 mol-1	webbook

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 Na₂Cl₂ (Disodium dichloride).

Rotational Constants (cm^-1)
See section I.F.4 to change rotational constant units

A	B	C	reference	comment

Calculated rotational constants for Na₂Cl₂ (Disodium dichloride).

Product of moments of inertia
	amu3Å6		0	gm3 cm6

Geometric Data

Point Group D_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
rNaCl	2.584		1	2			1992Kuchitsu(II/21)
aClNaCl	101.4		2	1	3		1992Kuchitsu(II/21)

Cartesians

Atom	x (Å)	y (Å)	z (Å)
Na1	0.0000	0.0000	0.0000
Cl2	1.9990	-1.6366	0.0000
Cl3	-1.9990	-1.6366	0.0000
Na4	0.0000	-3.2732	0.0000

Atom - Atom Distances
Distances in Å

	Na1	Cl2	Cl3	Na4
Na1		2.5835	2.5835	3.2732
Cl2	2.5835		3.9980	2.5835
Cl3	2.5835	3.9980		2.5835
Na4	3.2732	2.5835	2.5835

Calculated geometries for Na₂Cl₂ (Disodium dichloride).

Experimental Bond Angles (degrees) from cartesians

atom1	atom2	atom3	angle		atom1	atom2	atom3	angle
Na1	Cl2	Na4	78.615		Na1	Cl3	Na4	78.615
Cl2	Na1	Cl3	101.385		Cl2	Na4	Cl3	101.385

Bond descriptions
Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond

Bond Type	Count
Na-Cl	4

Connectivity

Atom 1	Atom 2
Na1	Cl2
Na1	Cl3
Cl2	Na4
Cl3	Na4

Electronic energy levels (cm^-1)

Energy (cm-1)	Degeneracy	reference	description
0	1		1Ag

Ionization Energies (eV)

Ionization Energy	I.E. unc.	vertical I.E.	v.I.E. unc.	Electron Affinity	E.A. unc.	reference
		10.300				webbook

Dipole, Quadrupole and Polarizability
Electric dipole moment
For a molecule with D_2h symmetry there is no dipole.
Electric quadrupole moment
Calculated electric quadrupole moments for Na₂Cl₂ (Disodium dichloride).

References
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squib	reference	DOI
1992Kuchitsu(II/21)	Kuchitsu (ed.), Landolt-Bornstein: Group II: Atomic and Molecular Physics Volume 21: Structure Data of Free Polyatomic Molecules. Springer-Verlag, Berlin, 1992.
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 (http://webbook.nist.gov/chemistry)

Got a better number? Please email us at cccbdb@nist.gov