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)		10.00	kJ mol-1	1990Fu/Lem:8420
Hfg(0K)	525.90	10.00	kJ mol-1	1990Fu/Lem:8420
Entropy (298.15K)	243.84	0.30	J K-1 mol-1	Gurvich
Integrated Heat Capacity (0 to 298.15K)	10.14		kJ mol-1	Gurvich
Heat Capacity (298.15K)	37.06		J K-1 mol-1	Gurvich

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
1	Σg	286	1990Fu/Lem:8420

Detailed diatomic data

ωe	ωexe	ωeye	Be	αe	ZPE	reference
285.8	0.9		0.17127	0.0008	142.6763	2007Iri:389

vibrational zero-point energy: 142.9 cm^-1
Calculated vibrational frequencies for Al₂^- (aluminum dimer anion).

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

A	B	C	reference	comment
	0.17127		1990Fu/Lem:8420	B0

Calculated rotational constants for Al₂^- (aluminum dimer anion).

Product of moments of inertia
98.42722	amu Å2		1.634448E-38	gm cm2

Geometric Data

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
rAlAl	2.701	0.002	1	2			1990Fu/Lem:8420

Cartesians

Atom	x (Å)	y (Å)	z (Å)
Al1	0.0000	0.0000	0.0000
Al2	0.0000	0.0000	2.7010

Atom - Atom Distances
Distances in Å

	Al1	Al2
Al1		2.7010
Al2	2.7010

Calculated geometries for Al₂^- (aluminum dimer anion).

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

Bond Type	Count
Al-Al	1

Connectivity

Atom 1	Atom 2
Al1	Al2

Electronic energy levels (cm^-1)

Energy (cm-1)	Degeneracy	reference	description
0	4	1990Fu/Lem:8420	3Σg
30.4	2	1990Fu/Lem:8420	1Σg
63.4	3	1990Fu/Lem:8420
17419.2	3	1990Fu/Lem:8420
24500	6	1990Fu/Lem:8420
27274.7	3	1990Fu/Lem:8420
28036	6	1990Fu/Lem:8420
30530.4	3	1990Fu/Lem:8420
31101.6	3	1990Fu/Lem:8420
32598.8	3	1990Fu/Lem:8420
34519.697	6	1990Fu/Lem:8420
38328.248	3	1990Fu/Lem:8420
38621.958	6	1990Fu/Lem:8420

Ionization Energies (eV)

Ionization Energy	I.E. unc.	vertical I.E.	v.I.E. unc.	Electron Affinity	E.A. unc.	reference	Comment
5.400	1.000			1.100	0.150	webbook	upper limit for EA

Dipole, Quadrupole and Polarizability
Electric dipole moment
For a molecule with D_∞h symmetry there is no dipole.
Electric quadrupole moment
Calculated electric quadrupole moments for Al₂^- (aluminum dimer anion).

References
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squib	reference	DOI
1990Fu/Lem:8420	Z Fu, GW Lemire, GA Bishea, MD Morse "Spectroscopy and electronic structure fo jet-cooled Al2" J. Chem. Phys. 93(12), 8420, 1990	10.1063/1.459280
2007Iri:389	KK Irikura "Experimental Vibrational Zero-Point Energies: Diatomic Molecules" J. Phys. Chem. Ref. Data 36(2), 389, 2007	10.1063/1.2436891
Gurvich	Gurvich, L.V.; Veyts, I. V.; Alcock, C. B., Thermodynamic Properties of Individual Substances, Fouth Edition, Hemisphere Pub. Co., New York, 1989	10.1351/pac198961061027
webbook	NIST Chemistry Webbook (http://webbook.nist.gov/chemistry)

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