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)	-27.85	3.20	kJ mol-1	Gurvich
Hfg(0K)	-27.54	3.20	kJ mol-1	Gurvich
Entropy (298.15K)	222.74		J K-1 mol-1	Gurvich
Integrated Heat Capacity (0 to 298.15K)	9.39		kJ mol-1	Gurvich
Heat Capacity (298.15K)	31.76		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	1233	1979HUB/HER

Detailed diatomic data

ωe	ωexe	ωeye	Be	αe	ZPE	reference
1233.34	6.56		0.7332237	5.466162E-03	615.1402	2007Iri:389

vibrational zero-point energy: 616.7 cm^-1
Calculated vibrational frequencies for PO^- (phosphorus monoxide anion).

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

A	B	C	reference	comment
	0.73370		1979HUB/HER

Calculated rotational constants for PO^- (phosphorus monoxide anion).

Product of moments of inertia
22.97619	amu Å2		3.815346E-39	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
rPO	1.476		1	2			1979HUB/HER

Cartesians

Atom	x (Å)	y (Å)	z (Å)
O1	0.0000	0.0000	0.0000
P2	0.0000	0.0000	1.4759

Atom - Atom Distances
Distances in Å

	O1	P2
O1		1.4759
P2	1.4759

Calculated geometries for PO^- (phosphorus monoxide anion).

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

Bond Type	Count
O=P	1

Connectivity

Atom 1	Atom 2
O1	P2

Electronic energy levels (cm^-1)

Energy (cm-1)	Degeneracy	reference	description
0	2	1979HUB/HER
224.03	2	1979HUB/HER

Ionization Energies (eV)

Ionization Energy	I.E. unc.	vertical I.E.	v.I.E. unc.	Electron Affinity	E.A. unc.	reference
8.390	0.010			1.000	0.100	webbook

Dipole, Quadrupole and Polarizability
Electric dipole moment
Calculated electric dipole moments for PO^- (phosphorus monoxide anion).
Electric quadrupole moment
Calculated electric quadrupole moments for PO^- (phosphorus monoxide 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