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)	229.79	6.10	kJ mol-1	Gurvich
Hfg(0K)	230.34	6.10	kJ mol-1	Gurvich
Entropy (298.15K)	193.20		J K-1 mol-1	Gurvich
Integrated Heat Capacity (0 to 298.15K)	8.68		kJ mol-1	Gurvich
Heat Capacity (298.15K)	29.59		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	Σ	1493	2007Iri:389

Detailed diatomic data

ωe	ωexe	ωeye	Be	αe	ZPE	reference
1492.776	29.84682	-0.30481	5.825523	0.1772981	739.1296	2007Iri:389

vibrational zero-point energy: 746.4 cm^-1
Calculated vibrational frequencies for MgH^- (magnesium monohydride anion).

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

A	B	C	reference	comment
	5.82552		2007Iri:389

Calculated rotational constants for MgH^- (magnesium monohydride anion).

Product of moments of inertia
2.893754	amu Å2		4.805263E-40	gm cm2

Geometric Data

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
rMgH	1.730		1	2			1979HUB/HER

Cartesians

Atom	x (Å)	y (Å)	z (Å)
Mg1	0.0000	0.0000	0.0000
H2	0.0000	0.0000	1.7297

Atom - Atom Distances
Distances in Å

	Mg1	H2
Mg1		1.7297
H2	1.7297

Calculated geometries for MgH^- (magnesium monohydride anion).

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

Bond Type	Count
H-Mg	1

Connectivity

Atom 1	Atom 2
Mg1	H2

Electronic energy levels (cm^-1)

Energy (cm-1)	Degeneracy	reference	description
0	2	1979HUB/HER	2Σ

Ionization Energies (eV)

Ionization Energy	I.E. unc.	vertical I.E.	v.I.E. unc.	Electron Affinity	E.A. unc.	reference
				1.050	0.060	webbook

Dipole, Quadrupole and Polarizability
Electric dipole moment
Calculated electric dipole moments for MgH^- (magnesium monohydride anion).
Electric quadrupole moment
Calculated electric quadrupole moments for MgH^- (magnesium monohydride anion).

References
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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
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)

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