Trihydrogen

Formula: H₃
Molecular weight: 3.02382
IUPAC Standard InChI: InChI=1S/H3/c1-2-3-1
IUPAC Standard InChIKey: FVJJEQURJXHDEY-UHFFFAOYSA-N
CAS Registry Number: 12184-91-7
Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript.
Other names: Trihydrogen (<sup>2</sup>p2A2"); H3
Permanent link for this species. Use this link for bookmarking this species for future reference.
Information on this page:
Options:
- Switch to calorie-based units

Vibrational and/or electronic energy levels

State: 3d ²A₁'

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o^a = 17255.11	gas	3d²A₁'-2p²A₂	568	615	Herzberg, Hougen, et al., 1982
					Bjerre, Hazell, et al., 1991
					Vervloet and Watson, 2003

State: 3d

Med.	Transition	λ_min (nm)	λ_max (nm)	References


gas	3d-3p²E'	2244	2570	Herzberg, Hougen, et al., 1982
				Vervloet and Watson, 2003

State: 3d ²E

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o^a = 17181.80	gas	3d²E''-2p²A₂	568	615	Herzberg, Hougen, et al., 1982
					Cosby and Helm, 1988
					Bjerre, Hazell, et al., 1991
					Vervloet and Watson, 2003

Vib. sym.	No.	Approximate type of mode	cm^-1	Med.	Method	References


a₁'	1	Sym. stretch	3168	gas	MPI	Lembo, Helm, et al., 1989 Lembo and Helm, 1989
e'	2	Deformation	2518	gas	EM PF	Ketterle, 1989

State: 3d ²E'

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o^a = 16878.69	gas	3d²E'-2p²A₂	568	615	Herzberg, Hougen, et al., 1982
					Vervloet and Watson, 2003

State: 3p ²A₂

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o^a = 16719.0 ± 0.8	gas	3p²A₂''-2p²A₂	556	574	Herzberg, 1979
					Dabrowski and Herzberg, 1980
					Herzberg, Hougen, et al., 1982
					Vervloet and Watson, 2003

State: 3s ²A₁'

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o^a = 16613.08 ± 0.16	gas	3s²A₁'-2p²A₂	592	615	Dabrowski and Herzberg, 1980
					Selgren and Gellene, 1988
					Cosby and Helm, 1988
					Vervloet and Watson, 2003

Vib. sym.	No.	Approximate type of mode	cm^-1	Med.	Method	References


a₁'	1	Sym. stretch	3212.1 ± 0.3	gas	MPI	Lembo, Helm, et al., 1989 Lembo and Helm, 1989
e'	2	Deformation	2588 ± 2	gas	EM PF	Ketterle, 1989

State: 3p ²E'

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o^a = 12966.86 ± 0.05	gas	3p²E'-2p²A₂	708	736	Herzberg, 1979
					Herzberg and Watson, 1980
					Vervloet and Watson, 2003
T_o^a	gas	3s²A₁'-3p²E'	2600	3147	Herzberg, Lew, et al., 1981

State: 2p ²A₂

Energy (cm^-1)	Med.	References


T_o^a = 0.0	gas	Dabrowski and Herzberg, 1980
		Herzberg, Lew, et al., 1981
		Vervloet and Watson, 2003

Vib. sym.	No.	Approximate type of mode	cm^-1	Med.	Method	References


a₁'	1	Sym. stretch	3255.38 ± 0.03	gas	PI	Lembo, Petit, et al., 1989 Ketterle, Messmer, et al., 1989 Lembo, Helm, et al., 1989
e'	2	Deformation	2618.34 ± 0.03	gas	PI	Ketterle, Messmer, et al., 1989

State: 2s ²A₁'

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o^a = -993	gas	3p²A₂''-2s²A₁'	556	564	Herzberg, 1979
					Dabrowski and Herzberg, 1980
T_o^a = -993	gas	3p²E'-2s²A₁'	708	736	Herzberg and Watson, 1980

Additional references: Jacox, 1994, page 12; Jacox, 1998, page 123; Jacox, 2003, page 9; Vogler, 1979; Watson, 1980; Figger, Moller, et al., 1982; Figger, Dixit, et al., 1984; Figger, Fukuda, et al., 1984; Raksit, Porter, et al., 1985; Helm, 1986; Helm, 1988; Dodhy, Ketterle, et al., 1988; Figger, Ketterle, et al., 1989; Ketterle, Figger, et al., 1989; Bordas, Cosby, et al., 1990; Bordas and Helm, 1991; Bordas, Lembo, et al., 1991; Bruckmeier, Wunderlich, et al., 1994; Muller, Majer, et al., 1997; Dabrowski and Herzberg, 1996; Azinovic and Figger, 1997; Muller, Braun, et al., 1998; Amano and Chan, 2000

Notes

Energy separation between the v = 0 levels of the excited and electronic ground states.

Separation of band origin for an excited state of H₃ or D₃ from the lowest bound state, 2s ²A₁'.

References

Go To: Top, Vibrational and/or electronic energy levels, Notes

Herzberg, Hougen, et al., 1982
Herzberg, G.; Hougen, J.T.; Watson, J.K.G., The electronic emission spectrum of triatomic hydrogen. IV. Visible bands near 5800 Å and infrared bands near 3950 cm, Can. J. Phys., 1982, 60, 9, 1261, https://doi.org/10.1139/p82-173 . [all data]

Bjerre, Hazell, et al., 1991
Bjerre, N.; Hazell, I.; Lorents, D.C., Spin---orbit coupling in H3, Chem. Phys. Lett., 1991, 181, 4, 301, https://doi.org/10.1016/0009-2614(91)80075-9 . [all data]

Vervloet and Watson, 2003
Vervloet, M.; Watson, J.K.G., Improved infrared and visible emission spectra of the H3 and D3 molecules, J. Mol. Spectrosc., 2003, 217, 2, 255, https://doi.org/10.1016/S0022-2852(02)00053-X . [all data]

Cosby and Helm, 1988
Cosby, P.C.; Helm, H., Photodissociation of Triatomic Hydrogen, Phys. Rev. Lett., 1988, 61, 3, 298, https://doi.org/10.1103/PhysRevLett.61.298 . [all data]

Lembo, Helm, et al., 1989
Lembo, L.J.; Helm, H.; Huestis, D.L., Measurement of vibrational frequencies of the H3 molecule using two-step photoionization, J. Chem. Phys., 1989, 90, 10, 5299, https://doi.org/10.1063/1.456434 . [all data]

Lembo and Helm, 1989
Lembo, L.J.; Helm, H., Observation of low-lying rydberg states of the triatomic hydrogen molecule, Chem. Phys. Lett., 1989, 163, 4-5, 425, https://doi.org/10.1016/0009-2614(89)85162-0 . [all data]

Ketterle, 1989
Ketterle, W., The bending vibration of n=3 states of H3, Chem. Phys. Lett., 1989, 160, 2, 139, https://doi.org/10.1016/0009-2614(89)87571-2 . [all data]

Herzberg, 1979
Herzberg, G., A spectrum of triatomic hydrogen, J. Chem. Phys., 1979, 70, 10, 4806, https://doi.org/10.1063/1.437272 . [all data]

Dabrowski and Herzberg, 1980
Dabrowski, I.; Herzberg, G., The electronic emission spectrum of triatomic hydrogen. I. Parallel bands of H, Can. J. Phys., 1980, 58, 8, 1238, https://doi.org/10.1139/p80-163 . [all data]

Selgren and Gellene, 1988
Selgren, S.F.; Gellene, G.I., Photo-assisted fragmentation spectroscopy of triatomic hydrogen, Chem. Phys. Lett., 1988, 146, 6, 485, https://doi.org/10.1016/0009-2614(88)87485-2 . [all data]

Herzberg and Watson, 1980
Herzberg, G.; Watson, J.K.G., The electronic emission spectrum of triatomic hydrogen. II. The perpendicular bands near 7100 Å, Can. J. Phys., 1980, 58, 8, 1250, https://doi.org/10.1139/p80-164 . [all data]

Herzberg, Lew, et al., 1981
Herzberg, G.; Lew, H.; Sloan, J.J.; Watson, J.K.G., The electronic emission spectrum of triatomic hydrogen. III. Infrared perpendicular bands near 3600 cm, Can. J. Phys., 1981, 59, 3, 428, https://doi.org/10.1139/p81-054 . [all data]

Lembo, Petit, et al., 1989
Lembo, L.J.; Petit, A.; Helm, H., Vibrational autoionization in H_{3} and measurements of the symmetric-stretch frequency of the metastable 2p A_{2}^{''} state, Phys. Rev. A, 1989, 39, 7, 3721, https://doi.org/10.1103/PhysRevA.39.3721 . [all data]

Ketterle, Messmer, et al., 1989
Ketterle, W.; Messmer, H.-P.; Walther, H., The ν, Europhys. Lett., 1989, 8, 4, 333, https://doi.org/10.1209/0295-5075/8/4/006 . [all data]

Jacox, 1994
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules, American Chemical Society, Washington, DC, 1994, 464. [all data]

Jacox, 1998
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules: supplement A, J. Phys. Chem. Ref. Data, 1998, 27, 2, 115-393, https://doi.org/10.1063/1.556017 . [all data]

Jacox, 2003
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules: supplement B, J. Phys. Chem. Ref. Data, 2003, 32, 1, 1-441, https://doi.org/10.1063/1.1497629 . [all data]

Vogler, 1979
Vogler, M., Observation of an electronically excited state of H_{3} and determination of its vibrational level structure, Phys. Rev. A, 1979, 19, 1, 1, https://doi.org/10.1103/PhysRevA.19.1 . [all data]

Watson, 1980
Watson, J.K.G., Predissociation spectrum of an excited electronic state of the H_{3} molecule, Phys. Rev. A, 1980, 22, 5, 2279, https://doi.org/10.1103/PhysRevA.22.2279 . [all data]

Figger, Moller, et al., 1982
Figger, H.; Moller, H.; Schrepp, W.; Walther, H., Laser spectroscopy ofD3, Chem. Phys. Lett., 1982, 90, 2, 90, https://doi.org/10.1016/0009-2614(82)83617-8 . [all data]

Figger, Dixit, et al., 1984
Figger, H.; Dixit, M.N.; Maier, R.; Schrepp, W.; Walther, H.; Peterkin, I.R.; Watson, J.K.G., Spectroscopy of Triatomic Hydrogen Molecules in a Beam, Phys. Rev. Lett., 1984, 52, 11, 906, https://doi.org/10.1103/PhysRevLett.52.906 . [all data]

Figger, Fukuda, et al., 1984
Figger, H.; Fukuda, Y.; Ketterle, W.; Walther, H., Spectra and lifetimes of triatomic hydrogen molecules, Can. J. Phys., 1984, 62, 12, 1274, https://doi.org/10.1139/p84-172 . [all data]

Raksit, Porter, et al., 1985
Raksit, A.B.; Porter, R.F.; Garver, W.P.; Leventhal, J.J., Bound-free ultraviolet emission from triatomic hydrogen, Phys. Rev. Lett., 1985, 55, 4, 378, https://doi.org/10.1103/PhysRevLett.55.378 . [all data]

Helm, 1986
Helm, H., Observation of high-n Rydberg series (7n40) of the H_{3} molecule, Phys. Rev. Lett., 1986, 56, 1, 42, https://doi.org/10.1103/PhysRevLett.56.42 . [all data]

Helm, 1988
Helm, H., Measurement of the ionization potential of triatomic hydrogen, Phys. Rev. A, 1988, 38, 7, 3425, https://doi.org/10.1103/PhysRevA.38.3425 . [all data]

Dodhy, Ketterle, et al., 1988
Dodhy, A.; Ketterle, W.; Messmer, H.-P.; Walther, H., A zero Kelvin Rydberg spectrum of H3, Chem. Phys. Lett., 1988, 151, 1-2, 133, https://doi.org/10.1016/0009-2614(88)80083-6 . [all data]

Figger, Ketterle, et al., 1989
Figger, H.; Ketterle, W.; Walther, H., Spectroscopy of triatomic hydrogen, Z. Phys. D, 1989, 13, 2, 129, https://doi.org/10.1007/BF01398582 . [all data]

Ketterle, Figger, et al., 1989
Ketterle, W.; Figger, H.; Walther, H., Spectroscopy of triatomic hydrogen, Z. Phys. D, 1989, 13, 2, 139, https://doi.org/10.1007/BF01398583 . [all data]

Bordas, Cosby, et al., 1990
Bordas, C.; Cosby, P.C.; Helm, H., Measurement of the lifetime of metastable triatomic hydrogen, J. Chem. Phys., 1990, 93, 9, 6303, https://doi.org/10.1063/1.458999 . [all data]

Bordas and Helm, 1991
Bordas, C.; Helm, H., Predissociation of H_{3} near its ionization threshold induced by very weak electric fields, Phys. Rev. A, 1991, 43, 7, 3645, https://doi.org/10.1103/PhysRevA.43.3645 . [all data]

Bordas, Lembo, et al., 1991
Bordas, M.C.; Lembo, L.J.; Helm, H., Spectroscopy and multichannel quantum-defect theory analysis of the np Rydberg series of H3, Phys. Rev. A, 1991, 44, 3, 1817, https://doi.org/10.1103/PhysRevA.44.1817 . [all data]

Bruckmeier, Wunderlich, et al., 1994
Bruckmeier, R.; Wunderlich, Ch.; Figger, H., New experimental insight into the ground state potential surface of triatomic hydrogen, Phys. Rev. Lett., 1994, 72, 16, 2550, https://doi.org/10.1103/PhysRevLett.72.2550 . [all data]

Muller, Majer, et al., 1997
Muller, U.; Majer, U.; Reichle, R.; Braun, M., Spectroscopy of high n Rydberg states of the triatomic deuterium molecule D[sub 3], J. Chem. Phys., 1997, 106, 19, 7958, https://doi.org/10.1063/1.473803 . [all data]

Dabrowski and Herzberg, 1996
Dabrowski, I.; Herzberg, G., Amazing Light, R. Y. Chiao, ed(s)., Springer-Verlag, New York, 1996, 173-190. [all data]

Azinovic and Figger, 1997
Azinovic, D.; Figger, H., Analysis of the molecular bands of D $_2$ H and H $_2$ D at 5600 ?, Z. Phys. D, 1997, 42, 2, 105, https://doi.org/10.1007/s004600050341 . [all data]

Muller, Braun, et al., 1998
Muller, U.; Braun, M.; Reichle, B.; Salzgeber, R.F., Vibrational frequencies of the 2p [sup 2]A[sub 2][sup ´´] and 3d [sup 2]E[sup ´´] states of the triatomic deuterium molecule, J. Chem. Phys., 1998, 108, 11, 4478, https://doi.org/10.1063/1.475859 . [all data]

Amano and Chan, 2000
Amano, T.; Chan, M.-C., Infrared absorption spectroscopy of D3: an investigation into the formation mechanisms of triatomic hydrogenic species, Phil. Trans. Roy. Soc. Lond. A, 2000, 358, 1774, 2457, https://doi.org/10.1098/rsta.2000.0660 . [all data]

Notes

Go To: Top, Vibrational and/or electronic energy levels, References

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
Customer support for NIST Standard Reference Data products.

Trihydrogen

Vibrational and/or electronic energy levels

State: 3d 2A1'

State: 3d

State: 3d 2E

State: 3d 2E'

State: 3p 2A2

State: 3s 2A1'

State: 3p 2E'

State: 2p 2A2

State: 2s 2A1'

Notes

References

Notes

State: 3d ²A₁'

State: 3d ²E

State: 3d ²E'

State: 3p ²A₂

State: 3s ²A₁'

State: 3p ²E'

State: 2p ²A₂

State: 2s ²A₁'