Hydrogen

• Formula: H₂
• Molecular weight: 2.01588
• IUPAC Standard InChI: InChI=1S/H2/h1H Copy

  
• IUPAC Standard InChIKey: UFHFLCQGNIYNRP-UHFFFAOYSA-N Copy
• CAS Registry Number: 1333-74-0
• 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.
• Isotopologues:
  • tritium
  • deuterium hydride
  • Deuterium
• Other names: Dihydrogen; o-Hydrogen; p-Hydrogen; Molecular hydrogen; H2; UN 1049; UN 1966
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Constants of diatomic molecules
  • References
  • Notes
• Other data available:
  • Phase change data
  • Reaction thermochemistry data: reactions 1 to 50, reactions 51 to 100, reactions 101 to 150, reactions 151 to 200, reactions 201 to 250, reactions 251 to 300, reactions 301 to 350, reactions 351 to 400, reactions 401 to 450, reactions 451 to 500, reactions 501 to 550, reactions 551 to 600, reactions 601 to 621
  • Henry's Law data
  • Gas phase ion energetics data
  • Ion clustering data
  • Mass spectrum (electron ionization)
  • Fluid Properties
• Data at other public NIST sites:
  • Electron-Impact Ionization Cross Sections (on physics web site)
  • Gas Phase Kinetics Database
• Options:
  • Switch to calorie-based units

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, "lite" edition (thermophysical and thermochemical data)
• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Gas phase thermochemistry data

Go To: Top, Constants of diatomic molecules, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Gas Phase Heat Capacity (Shomate Equation)

C_p° = A + B*t + C*t² + D*t³ + E/t²
H° − H°_298.15= A*t + B*t²/2 + C*t³/3 + D*t⁴/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t²/2 + D*t³/3 − E/(2*t²) + G
    C_p = heat capacity (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

View plot Requires a JavaScript / HTML 5 canvas capable browser.

View table.

Constants of diatomic molecules

Go To: Top, Gas phase thermochemistry data, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: Klaus P. Huber and Gerhard H. Herzberg

Data collected through November, 1976

Notes

References

Go To: Top, Gas phase thermochemistry data, Constants of diatomic molecules, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Cox, Wagman, et al., 1984
Cox, J.D.; Wagman, D.D.; Medvedev, V.A., CODATA Key Values for Thermodynamics, Hemisphere Publishing Corp., New York, 1984, 1. [all data]

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Crosswhite, 1972
Crosswhite, H.M., The hydrogen molecule wavelength tables of Gerhard Heinrich Dieke, Wiley-Interscience, Division of John Wiley & Sons, Inc., New York, 1972, 616. [all data]

Dieke, 1958
Dieke, G.H., The molecular spectrum of hydrogen and its isotopes, J. Mol. Spectrosc., 1958, 2, 494. [all data]

Sharp, 1971
Sharp, T.E., Potential-energy curves for molecular hydrogen and its ions, At. Data, 1971, 2, 119. [all data]

Richardson, 1934
Richardson, O.W., Molecular Hydrogen and Its Spectrum, Yale University Press, New Haven, 1934, 343. [all data]

Richardson, Yarrow, et al., 1934
Richardson, O.W.; Yarrow, F.R.S.; Rymer, T.B., The spectrum of H₂. Part III. New bands and band systems ending on 2s ³Σ and an extension of the singlet system ¹Q → 2p ¹Σ, Proc. R. Soc. London A, 1934, 147, 272. [all data]

Richardson, Yarrow, et al., 1934, 2
Richardson, O.W.; Yarrow, F.R.S.; Rymer, T.B., The spectrum of H₂. Part II - The band systems due to transitions from four new triplet states to 2p ³Π, Proc. R. Soc. London A, 1934, 147, 251. [all data]

Foster and Richardson, 1953
Foster, E.W.; Richardson, O., The fine structure of the 4d³Σ, ³Π_cd, ³Δ_d → 2p ³Π_cd transitions of the H₂ spectrum, Proc. R. Soc. London A, 1953, 217, 433. [all data]

Miller and Freund, 1975
Miller, T.A.; Freund, R.S., Anticrossings and microwave transitions between the k(4p) ³Π_u, v = 1, N = 3 and the p(4d) ³Σ_g⁺, v = 1, N = 5 levels of H₂, J. Chem. Phys., 1975, 62, 2240. [all data]

Cunningham and Dieke, 1950
Cunningham; Dieke, Johns Hopkins University, Department of Physics, Rpt. NYO-692, 1950, 1. [all data]

Freund and Miller, 1974
Freund, R.S.; Miller, T.A., Anticrossings and microwave transitions between electronic states of H₂, J. Chem. Phys., 1974, 60, 4900. [all data]

Gloersen and Dieke, 1965
Gloersen, P.; Dieke, G.H., Molecular spectra of hydrogen and helium in the infrared, J. Mol. Spectrosc., 1965, 16, 191. [all data]

Richardson, Yarrow, et al., 1934, 3
Richardson, O.W.; Yarrow, F.R.S.; Rymer, T.B., The spectrum of H₂ (the ordinary hydrogen molecule). Part I - The 3, 4d ³Σ, Π, Δ → 2p ³Π and 3s ³Σ → 2p ³Π systems, Proc. R. Soc. London A, 1934, 147, 24. [all data]

Dieke and Blue, 1935
Dieke, G.H.; Blue, R.W., The Fulcher bands of HD and D₂, Phys. Rev., 1935, 47, 261. [all data]

Dieke, 1935
Dieke, G.H., The 3p³Σ→2s³Σ bands of HD and D₂, Phys. Rev., 1935, 48, 606. [all data]

Kolos and Wolniewicz, 1965
Kolos, W.; Wolniewicz, L., Potential-energy curves for the X¹Σ_g⁺, b³Σ_u⁺, and C¹Π_u states of the hydrogen molecule, J. Chem. Phys., 1965, 43, 2429. [all data]

Herzberg, 1969
Herzberg, G., Dissociation energy and ionization potential of molecular hydrogen, Phys. Rev. Letters, 1969, 23, 1081. [all data]

Takezawa, 1970
Takezawa, S., Absorption spectrum of H₂ in the vacuum-uv region. I. Rydberg states and ionization energies, J. Chem. Phys., 1970, 52, 2575. [all data]

Dabrowski and Herzberg, 1974
Dabrowski, I.; Herzberg, G., The absorption spectrum of D₂ from 1100 to 840 Å, Can. J. Phys., 1974, 52, 1110. [all data]

Chupka, Dehmer, et al., 1975
Chupka, W.A.; Dehmer, P.M.; Jivery, W.T., High resolution photoionization study of ion-pair formation in H₂, HD, and D₂, J. Chem. Phys., 1975, 63, 3929. [all data]

Kolos, 1976
Kolos, W., Ab initio potential energy curves and vibrational levels for the B", B«macron», and B'¹Σ_u+ states of the hydrogen molecule, J. Mol. Spectrosc., 1976, 62, 429. [all data]

Monfils, 1965
Monfils, A., The absorption spectra of the molecules H₂, HD, and D₂. Part VI. Rotational analysis of the B', B", D, D', and D" states, J. Mol. Spectrosc., 1965, 15, 265. [all data]

Monfils, 1968
Monfils, A., Absorption spectra of molecules H₂, HD, and D₂. VII. Vibrational constants of the B, B', B", C, D, D', and D" states, J. Mol. Spectrosc., 1968, 25, 513. [all data]

Namioka, 1964
Namioka, T., Absorption spectra of H₂ in the vacuum ultraviolet region. II. The B'-X, B"-X, D-X, and D'-X bands, J. Chem. Phys., 1964, 41, 2141. [all data]

Richardson, 1937
Richardson, O.W., The band systems ending on the 1sσ 2sσ¹Σ_g(¹X_g) state of H₂. Part I., Proc. R. Soc. London A, 1937, 160, 487-507. [all data]

Dieke and Lewis, 1937
Dieke, G.H.; Lewis, M.N., Bands of HD and D₂ ending on the 2p¹Σ state, Phys. Rev., 1937, 52, 100. [all data]

Porto and Jannuzzi, 1963
Porto, S.P.S.; Jannuzzi, N., New singlet transitions in the near infrared spectrum of molecular hydrogen, J. Mol. Spectrosc., 1963, 11, 378. [all data]

Namioka, 1965
Namioka, T., Absorption spectra of H₂ in the vacuum-ultraviolet region. III. Potential-energy curves for the B¹Σ_u⁺, C¹Π_u, B'¹Σ_u⁺, and D¹Π_u states, J. Chem. Phys., 1965, 43, 1636. [all data]

Dieke, 1949
Dieke, G.H., Bands from doubly excited levels of the hydrogen molecule, Phys. Rev., 1949, 76, 50. [all data]

Dieke, 1936
Dieke, G.H., The 2s¹Σ→2p¹Σ bands of the hydrogen molecule, Phys. Rev., 1936, 50, 797. [all data]

Porto and Dieke, 1955
Porto, S.P.S.; Dieke, G.H., Infrared spectrum of hydrogen and deuterium between one and two microns, J. Opt. Soc. Am., 1955, 45, 447. [all data]

Dieke, 1938
Dieke, G.H., Bands of H₂ ending on the 2p¹Π level, Phys. Rev., 1938, 54, 439. [all data]

Namioka, 1964, 2
Namioka, T., Absorption spectra of H₂ in the vacuum-ultraviolet region. I. The Lyman and the Werner bands, J. Chem. Phys., 1964, 40, 3154. [all data]

Herzberg and Howe, 1959
Herzberg, G.; Howe, L.L., The Lyman bands of molecular hydrogen, Can. J. Phys., 1959, 37, 636. [all data]

Wilkinson, 1968
Wilkinson, P.G., The electronic isotope shift in the Lyman bands of H₂, HD, and D₂, Can. J. Phys., 1968, 46, 1225. [all data]

Herzberg, 1950
Herzberg, G., Forbidden transitions in diatomic molecules. I. The quadrupole rotation-vibration spectrum of H₂, Can. J. Res. Sect. A, 1950, 28, 144. [all data]

Fink, Wiggins, et al., 1965
Fink, U.; Wiggins, T.A.; Rank, D.H., Frequency and intensity measurements on the quadrupole spectrum of molecule hydrogen, J. Mol. Spectrosc., 1965, 18, 384. [all data]

Terhune and Peters, 1959
Terhune, R.W.; Peters, C.W., Electric field induced vibration rotation spectrum of H₂ and D₂, J. Mol. Spectrosc., 1959, 3, 138. [all data]

Foltz, Rank, et al., 1966
Foltz, J.V.; Rank, D.H.; Wiggins, T.A., Determinations of some hydrogen molecular constants, J. Mol. Spectrosc., 1966, 21, 203. [all data]

Brannon, Church, et al., 1968
Brannon, P.J.; Church, C.H.; Peters, C.W., Electric field induced spectra of molecular hydrogen, deuterium and deuterium hydride, J. Mol. Spectrosc., 1968, 27, 44. [all data]

Stoicheff, 1957
Stoicheff, B.P., High resolution Raman spectroscopy of gases. IX. Spectra of H₂, HD, and D₂, Can. J. Phys., 1957, 35, 730. [all data]

Harrick and Ramsey, 1952
Harrick, N.J.; Ramsey, N.F., Rotational magnetic moment, magnetic susceptibilities, and electron distribution in the hydrogen molecule, Phys. Rev., 1952, 88, 228. [all data]

Barnes, Bray, et al., 1954
Barnes, R.G.; Bray, P.J.; Ramsey, N.F., Variations of hydrogen rotational magnetic moments with rotational quantum number and with isotopic mass, Phys. Rev., 1954, 94, 893. [all data]

Kolsky, Phipps, et al., 1952
Kolsky, H.G.; Phipps, T.E., Jr.; Ramsey, N.F.; Silsbee, H.B., Nuclear radiofrequency spectra of H₂ and D₂ in high and low magnetic fields, Phys. Rev., 1952, 87, 395. [all data]

Harrick, Barnes, et al., 1953
Harrick, N.J.; Barnes, R.G.; Bray, P.J.; Ramsey, N.F., Nuclear radiofrequency spectra of D₂ and H₂ in intermediate and strong magnetic fields, Phys. Rev., 1953, 90, 260. [all data]

Ginter, 1967
Ginter, M.L., Molecular constants for the l-uncoupled electronic states 3d ^1,3Δ_g and 3d ^1,3Π_g of the hydrogen molecule, J. Chem. Phys., 1967, 46, 3687. [all data]

Freund, Miller, et al., 1973
Freund, R.S.; Miller, T.A.; Zegarski, B.R., Fine structure of para H₂, k(4p)³Π_u, Chem. Phys. Lett., 1973, 23, 120. [all data]

Miller, Freund, et al., 1974
Miller, T.A.; Freund, R.S.; Zagarski, B.R., Fine and hyperfine structure of ortho-H₂, k(4p) ³Π_u, J. Chem. Phys., 1974, 60, 3195. [all data]

Ginter, 1966
Ginter, M.L., Spectrum and structure of the He₂ molecule. IV. Characterization of the singlet and triplet states associated with the UAO's 3dσ, 3dπ, and 3dδ, J. Chem. Phys., 1966, 45, 248. [all data]

Herzberg, 1967
Herzberg, G., A new predissociation of the H₂ molecule, Sci. Light (Tokyo), 1967, 16, 14. [all data]

Browne, 1965
Browne, J.C., Quantum mechanical potential energy curves for the ¹Π_u and ³Π_u states of He₂ and the ¹Π_g and ³Π_g states of H₂, Phys. Rev. A: Gen. Phys., 1965, 138, 9. [all data]

Wright and Davidson, 1965
Wright, W.M.; Davidson, E.R., 1s₃d ³Π_g state of the hydrogen molecule, J. Chem. Phys., 1965, 43, 840. [all data]

Freund and Miller, 1973
Freund, R.S.; Miller, T.A., Fine structure of para-H₂ d(3p) ³Π_u (ν=0-3) via microwave optical magnetic resonance induced by electrons, J. Chem. Phys., 1973, 58, 3565. [all data]

Dieke, 1935, 2
Dieke, G.H., The triplet 3p complex of the hydrogen molecule, Phys. Rev., 1935, 48, 610. [all data]

Beutler and Junger, 1936
Beutler, H.; Junger, H.-O., Pradissoziation und autoionisierung in den termfolgen des Wasserstoff-(H₂^-) spektrums, Z. Phys., 1936, 101, 285. [all data]

Cahill, 1969
Cahill, P., Determination of the lifetime of the d³Π_u state of H₂, J. Opt. Soc. Am., 1969, 59, 875. [all data]

Marechal, Jost, et al., 1972
Marechal, M.A.; Jost, R.; Lombardi, M., Lifetimes, g factors, and collision cross sections of hydrogen molecules in the (1s₃p) ³Π_u level, Phys. Rev. A: Gen. Phys., 1972, 5, 732. [all data]

Miller and Freund, 1974
Miller, T.A.; Freund, R.S., Singlet-triplet anticrossings in H₂, J. Chem. Phys., 1974, 61, 2160. [all data]

Jost and Lombardi, 1974
Jost, R.; Lombardi, M., Determination of the singlet-triplet separation of H₂ by a "level-anticrossing" technique, Phys. Rev. Lett., 1974, 33, 53. [all data]

Kolos, 1975
Kolos, W., Revised theoretical energy for the a³Σ_g⁺ state of H₂, Chem. Phys. Lett., 1975, 31, 43. [all data]

Kolos and Wolniewicz, 1968
Kolos, W.; Wolniewicz, L., Vibrational and rotational energies of the B¹Σ_u⁺, C¹Π_u, C¹Π_u, and a³Σ_g⁺ states of the hydrogen molecule, J. Chem. Phys., 1968, 48, 3672. [all data]

Smith and Chevalier, 1972
Smith, W.H.; Chevalier, R., Radiative-lifetime studies of the emission continua of the hydrogen and deuterium molecules, Astrophys. J., 1972, 177, 835. [all data]

King, Read, et al., 1975
King, G.C.; Read, F.H.; Imhof, R.E., The measurement of molecular lifetimes by the photon-photon delayed coincidence method, J. Phys. B:, 1975, 8, 665. [all data]

Jette, 1974
Jette, A.N., Spin-other-orbit and spin-spin interactions in the metastable, C³Π_u(1s,2p) state of H₂, J. Chem. Phys., 1974, 61, 816. [all data]

Jette and Miller, 1974
Jette, A.N.; Miller, T.A., Fine structure in Rydberg states of the H₂ molecule, Chem. Phys. Lett., 1974, 29, 547. [all data]

Lichten, 1960
Lichten, W., Metastable hydrogen molecules, Phys. Rev., 1960, 120, 848. [all data]

Frey and Mizushima, 1962
Frey, D.A.; Mizushima, M., Hyperfine structure of the hydrogen molecule in its metastable ³Π_u state, Phys. Rev., 1962, 128, 2683. [all data]

Lichten, 1962
Lichten, W., Measurements of lifetimes of metastable hydrogen molecules: a forbidden predissociation in H₂, Bull. Am. Phys. Soc., 1962, 7, 43. [all data]

Chiu, 1964
Chiu, L.-Y.C., Electron magnetic perturbation in diatomic molecules of Hund's case b, J. Chem. Phys., 1964, 40, 2276. [all data]

Johnson, 1972
Johnson, C.E., Lifetime of the c³Π_u metastable state of H₂, D₂, and HD, Phys. Rev. A: Gen. Phys., 1972, 5, 1026. [all data]

Johnson, 1974
Johnson, C.E., Quenching of the c³Π_u metastable state of H₂ and D₂ by an electric field, Phys. Rev. A: Gen. Phys., 1974, 9, 576. [all data]

Kagann and English, 1976
Kagann, R.H.; English, T.C., Stark-Zeeman effect of metastable orthohydrogen and parahydrogen, Phys. Rev. A: Gen. Phys., 1976, 13, 1451. [all data]

English and Albritton, 1975
English, T.C.; Albritton, D.L., Theory of the Stark effect of metastable parahydrogen, J. Phys. B:, 1975, 8, 2123. [all data]

Dunn, 1966
Dunn, G.H., Franck-Condon factors for the ionization of H₂ and D₂, J. Chem. Phys., 1966, 44, 2592. [all data]

Villarejo, 1968
Villarejo, D., Vibration-rotation interaction effects in calculated Franck-Condon factors. I. The ionization of H₂ and D₂, J. Chem. Phys., 1968, 49, 2523. [all data]

Nicholls, 1968
Nicholls, R.W., Franck-Condon factors for ionizing transitions of O₂, CO, NO and H₂ and for the NO⁺(A¹-Σx¹Σ) band system, J. Phys. B:, 1968, 1, 1192. [all data]

Ford, Docken, et al., 1975
Ford, A.L.; Docken, K.K.; Dalgarno, A., Cross sections for photoionization of vibrationally excited molecular hydrogen, Astrophys. J., 1975, 200, 788. [all data]

Villarejo, 1968, 2
Villarejo, D., Measurement of threshold electrons in the photoionization of H₂ and D₂, J. Chem. Phys., 1968, 48, 4014. [all data]

Turner, 1968
Turner, D.W., High resolution molecular photoelectron spectroscopy. I. Fine structure in the spectra of hydrogen and oxygen, Proc. Roy. Soc. (London), 1968, A307, 15. [all data]

Chupka and Berkowitz, 1968
Chupka, W.A.; Berkowitz, J., Photoionization of the H₂ molecule near threshold, J. Chem. Phys., 1968, 48, 5726. [all data]

Comes and Wellern, 1968
Comes, F.J.; Wellern, H.O., Die Spektroskopie des Wasserstoffmolekuls in der Nahe seiner Ionisierungs-grenze., Z. Naturforsch., 1968, 23a, 881. [all data]

Backx, Wight, et al., 1976
Backx, C.; Wight, G.R.; van der Wiel, M.J., Oscillator strengths (10-70 eV) for absorption, ionization and dissociation in H₂, HD and D₂, obtained by an electron-ion coincidence method, J. Phys. B:, 1976, 9, 315. [all data]

Herzberg and Jungen, 1972
Herzberg, G.; Jungen, Ch., Rydberg series and ionization potential of the H₂ molecule, J. Mol. Spectrosc., 1972, 41, 425. [all data]

Monfils, 1968, 2
Monfils, A., Calcul des fonctions potentielles de divers etats signulets excites des molecules H₂, HD et D₂, Bull. Cl. Sci. Acad. R. Belg., 1968, 54, 44. [all data]

Herzberg, 1971
Herzberg, G., Beutler-Fano shape in the predissociation of H₂ in Topics in Modern Physics, W.E. Brittin; Odabasi,H., ed(s)., Colorado Associated University Press, Boulder, Colorado, 1971, 191-197. [all data]

Comes and Schumpe, 1971
Comes, F.J.; Schumpe, G., Einfluss der Rotation auf die Lebensdauer pradissoziierender Molekule, Z. Naturforsch. A, 1971, 26, 538. [all data]

Fiquet-Fayard and Gallais, 1971
Fiquet-Fayard, F.; Gallais, O., Calculs numeriques de facteurs de Franck-Condon et effets isotopiques: perturbation de H₂ C¹Π_u et predissociation de H₂ D¹Π_u, Mol. Phys., 1971, 20, 527. [all data]

Julienne, 1971
Julienne, P.S., Predissociation of the H₂ D¹Π_u state, Chem. Phys. Lett., 1971, 8, 27. [all data]

Fiquet-Fayard and Gallais, 1972
Fiquet-Fayard, F.; Gallais, O., Predissociation of H₂ and D₂ (D¹Π_u): comparison of calculated and experimental line-widths, Chem. Phys. Lett., 1972, 16, 18. [all data]

Comes and Wenning, 1969
Comes, F.J.; Wenning, U., Photoinduzierte Stossprozesse metastabiler Wasserstoffatome mit H₂ im Energiebereich von 0,05 - 0,47 eV, Z. Naturforsch. A, 1969, 24, 587. [all data]

Mentall and Gentieu, 1970
Mentall, J.E.; Gentieu, E.P., Lyman-α fluorescence from the photodissociation of H₂, J. Chem. Phys., 1970, 52, 5641. [all data]

Comes and Wenning, 1970
Comes, F.J.; Wenning, U., Pradissoziation im elektrischen Feld - ein neues Phanomen in der Molekulspektroskopie, Z. Naturforsch. A, 1970, 25, 406. [all data]

Spindler, 1969
Spindler, R.J., Jr., Franck-Condon factors for band systems of molecular hydrogen. I. The (B¹Σ_u⁺ - X¹Σ_g⁺), (I¹Π_g - B¹Σ_u⁺) and (d³Π_u - a³Σ_g⁺) systems, J. Quant. Spectrosc. Radiat. Transfer, 1969, 9, 597. [all data]

Cook and Metzger, 1964
Cook, G.R.; Metzger, P.H., Photoionization and absorption cross sections of H₂ and D₂ in the vacuum ultraviolet region, J. Opt. Soc. Am., 1964, 54, 968. [all data]

Lewis, 1974
Lewis, B.R., Experimentally-determined oscillator strengths for molecular hydrogen. II. The Lyman and Werner bands below 900 Å, the B'-X and the D-X bands, J. Quant. Spectrosc. Radiat. Transfer, 1974, 14, 537. [all data]

Mulliken, 1964
Mulliken, R.S., Rare-gas and hydrogen molecule electronic states, noncrossing rule, and recombination of electrons with rare-gas and hydrogen ions, Phys. Rev., 1964, 136, 962. [all data]

Dieke, Cunningham, et al., 1953
Dieke, G.H.; Cunningham, S.P.; Byrne, F.T., The Zeeman effect in the molecular spectra of hydrogen, Phys. Rev., 1953, 92, 81. [all data]

van der Linde and Dalby, 1972
van der Linde, J.; Dalby, F.W., Zero field level crossing in excited states of molecular hydrogen, Can. J. Phys., 1972, 50, 287. [all data]

Melieres-Marechal and Lombardi, 1974
Melieres-Marechal, M.-A.; Lombardi, M., Weak hyperfine structure measurement using the magnetic repolarization effect: application to N = 1 v = 1 (1s₃d)¹Σ, J. Chem. Phys., 1974, 61, 2600. [all data]

Freund and Miller, 1972
Freund, R.S.; Miller, T.A., Microwave optical magnetic resonance induced by electrons (MOMRIE) in H₂ G(3d ¹Σ_g⁺), J. Chem. Phys., 1972, 56, 2211. [all data]

Ford, Browne, et al., 1975
Ford, A.L.; Browne, J.C.; Shipsey, E.J.; DeVries, P., Adiabatic ab initio potential curves for the B' ¹Σ_u⁺ state of H₂, J. Chem. Phys., 1975, 63, 362. [all data]

Wolniewicz, 1975
Wolniewicz, L., Theoretical investigation of the B'¹Σ_u⁺ state of the hydrogen molecule, Chem. Phys. Lett., 1975, 31, 248. [all data]

Davidson, 1961
Davidson, E.R., First excited ¹Σ_g⁺ state of the hydrogen molecule, J. Chem. Phys., 1961, 35, 1189. [all data]

Kolos and Wolniewicz, 1969
Kolos, W.; Wolniewicz, L., Theoretical investigation of the lowest double-minimum state E, F¹Σ_g⁺ of the hydrogen molecule, J. Chem. Phys., 1969, 50, 3228. [all data]

Lin, 1974
Lin, C.S., Theoretical analysis of the vibrational structure of the electronic transitions involving a state with double minimum: E,F ¹Σ_g⁺ of H₂, J. Chem. Phys., 1974, 60, 4660. [all data]

Wolniewicz, 1969
Wolniewicz, L., Theoretical investigation of the transition probabilities in the hydrogen molecule, J. Chem. Phys., 1969, 51, 5002. [all data]

King and Van Vleck, 1939
King, G.W.; Van Vleck, J.H., Dipole-dipole resonance forces, Phys. Rev., 1939, 55, 1165. [all data]

Mulliken, 1960
Mulliken, R.S., The interaction of differently excited like atoms at large distances, Phys. Rev., 1960, 120, 1674. [all data]

Rothenberg and Davidson, 1966
Rothenberg, S.; Davidson, E.R., Hydrogen-molecule excited states: ¹Π_u, J. Chem. Phys., 1966, 44, 730. [all data]

Kolos, 1967
Kolos, W., Long-range interaction between 1s and 2s or 2p hydrogen atoms, Int. J. Quantum Chem., 1967, 1, 169. [all data]

Julienne, 1973
Julienne, P.S., Nonadiabatic effects in the B, C, B', and D states of H₂, J. Mol. Spectrosc., 1973, 48, 508. [all data]

Ford, 1974
Ford, A.L., Lambda-Doubling in the C¹Π_u state of H₂, J. Mol. Spectrosc., 1974, 53, 364. [all data]

Hesser, 1968
Hesser, J.E., Absolute Transition Probabilities in Ultraviolet Molecular Spectra, J. Chem. Phys., 1968, 48, 6, 2518, https://doi.org/10.1063/1.1669477 . [all data]

Geiger and Schmoranzer, 1969
Geiger, J.; Schmoranzer, H., Electronic and vibrational transition probabilities of isotopic hydrogen molecules H₂, HD, and D₂ based on electron energy loss spectra, J. Mol. Spectrosc., 1969, 32, 39. [all data]

Schmoranzer and Geiger, 1973
Schmoranzer, H.; Geiger, J., Light emission of electron impact excited hydrogen molecules and the dependence of electronic transition moment on internuclear distance, J. Chem. Phys., 1973, 59, 6153. [all data]

Fabian and Lewis, 1974
Fabian, W.; Lewis, B.R., Experimentally determined oscillator strengths for molecular hydrogen. I. The Lyman and Werner bands above 900 Å, J. Quant. Spectrosc. Radiat. Transfer, 1974, 14, 523. [all data]

Allison and Dalgarno, 1970
Allison, A.C.; Dalgarno, A., Band oscillator strengths and transition probabilities for the Lyman and Werner systems of H₂, HD, and D₂, At. Data, 1970, 1, 289. [all data]

Allison and Dalgarno, 1970, 2
Allison, A.C.; Dalgarno, A., Isotope effects in the Lyman and Werner systems of molecular hydrogen, Mol. Phys., 1970, 19, 567. [all data]

Dalgarno and Stephens, 1970
Dalgarno, A.; Stephens, T.L., Discrete absorption and photodissociation of molecular hydrogen, Astrophys. J., 1970, 160, 107. [all data]

Stephens and Dalgarno, 1972
Stephens, T.L.; Dalgarno, A., Spontaneous radiative dissociation in molecular hydrogen, J. Quant. Spectrosc. Radiat. Transfer, 1972, 12, 569. [all data]

Takezawa, Innes, et al., 1966
Takezawa, S.; Innes, F.R.; Tanaka, Y., Selective enhancement in hydrogenlike molecules with the rare gases. I. H₂ with Ar and Kr, J. Chem. Phys., 1966, 45, 2000. [all data]

Hodson and Dreyfus, 1972
Hodson, R.T.; Dreyfus, R.W., Vacuum-UV laser action observed in H₂ Werner bands: 1161-1240 Å, Phys. Rev. Lett., 1972, 28, 536. [all data]

Waynant, 1972
Waynant, R.W., Observations of gain by stimulated emission in the Werner band of molecular hydrogen, Phys. Rev. Lett., 1972, 28, 533. [all data]

Herzberg, 1970
Herzberg, G., The dissociation energy of the hydrogen molecule, J.Mol. Spectry., 1970, 33, 147. [all data]

Tobias and Vanderslice, 1961
Tobias, I.; Vanderslice, J.T., Potential energy curves for the X¹Σ_g⁺ and B¹Σ_u⁺ states of hydrogen, J. Chem. Phys., 1961, 35, 1852. [all data]

Stwalley, 1973
Stwalley, W.C., Potential energy curve of the B¹Σ_u⁺ state of H₂, J. Chem. Phys., 1973, 58, 536. [all data]

Kolos and Wolniewicz, 1975
Kolos, W.; Wolniewicz, L., New ab initio potential energy curve and vibrational levels for the B¹Σ_u⁺ state of the hydrogen molecule, Can. J. Phys., 1975, 53, 2189. [all data]

Halmann and Laulicht, 1966
Halmann, M.; Laulicht, I., Isotope effects on Franck-Condon factors. V. Electronic transitions of isotopic O₂, N₂, C₂, and H₂ molecules, J. Chem. Phys., 1966, 44, 2398. [all data]

Dalgarno and Allison, 1968
Dalgarno, A.; Allison, A.C., Band oscillator strengths of the Lyman system of molecular hydrogen, Astrophys. J., 1968, 154, 95. [all data]

Lin, 1975
Lin, C.S., Calculation of the Franck-Condon factors: single-α approximation method, Can. J. Phys., 1975, 53, 310. [all data]

Villarejo, Stockbauer, et al., 1969
Villarejo, D.; Stockbauer, R.; Inghram, M.G., Vibration-rotation interaction effects in calculated Franck-Condon factors. II. Hydrogen Lyman and Fulcher bands, J. Chem. Phys., 1969, 50, 1754. [all data]

Becker and Fink, 1971
Becker, K.H.; Fink, E.H., Relative line intensities in the Lyman bands of HD and H₂, Z. Naturforsch. A, 1971, 26, 319. [all data]

Geiger and Topschowsky, 1966
Geiger, J.; Topschowsky, M., Ubergangswahrscheinlichkeiten im Elektronen- und Schwingungsspektrum des Wasserstoffmolekuls, Z. Naturforsch. A, 1966, 21, 626. [all data]

Haddad, Lokan, et al., 1968
Haddad, G.N.; Lokan, K.H.; Farmer, A.J.D.; Carver, J.H., An experimental determination of the oscillator strengths for some transitions in the Lyman bands of molecular hydrogen, J. Quant. Spectrosc. Radiat. Transfer, 1968, 8, 1193. [all data]

Hesser, Brooks, et al., 1968
Hesser, J.E.; Brooks, N.H.; Lawrence, G.M., H₂ Lyman-band oscillator strengths, J. Chem. Phys., 1968, 49, 5388. [all data]

Schmoranzer, 1975
Schmoranzer, H., Electronic transition moment in the B¹Σ_u⁺ -X¹Σ_g⁺ Lyman band system of H₂ based on keV electron impact excited vacuum UV emission intensities, J. Phys. B:, 1975, 8, 1139. [all data]

Hodgson, 1970
Hodgson, R.T., Vacuum-ultraviolet laser action observed in the Lyman bands of molecular hydrogen, Phys. Rev. Lett., 1970, 25, 494. [all data]

Waynant, Shipman, et al., 1970
Waynant, R.W.; Shipman, J.D., Jr.; Elton, R.C.; Ali, A.W., Vacuum ultraviolet laser emission from molecular hydrogen, Appl. Phys. Lett., 1970, 17, 383. [all data]

Dalgarno, Herzberg, et al., 1970
Dalgarno, A.; Herzberg, G.; Stephens, T.L., A new continuous emission spectrum of the hydrogen molecule, Astrophys. J., 1970, 162, 49. [all data]

Allison and Dalgarno, 1969
Allison, A.C.; Dalgarno, A., Photodissociation of vibrationally excited H₂, HD, and D₂ by absorption into the continua of the Lyman and Werner systems, At. Data, 1969, 1, 91. [all data]

Herzberg and Monfils, 1960
Herzberg, G.; Monfils, A., The dissociation energies of the H₂, HD, and D₂ molecules, J. Mol. Spectrosc., 1960, 5, 482. [all data]

Weissman, Vanderslice, et al., 1963
Weissman, S.; Vanderslice, J.T.; Battino, R., On the recalculation of the potential curves for the ground states of I₂ and H₂, J. Chem. Phys., 1963, 39, 2226. [all data]

Ginter and Battino, 1965
Ginter, M.L.; Battino, R., On the calculation of potential curves by the Rydberg-Klein-Rees method. I. Experimental limitations, extrapolation procedures, and applications to the third-group hydrides, J. Chem. Phys., 1965, 42, 3222. [all data]

Zhirnov and Vasilevskii, 1970
Zhirnov, N.I.; Vasilevskii, A.S., A new method for constructing the potential curves of diatomic molecules on the basis of spectroscopic data. IV. The potential curve of the ground electronic state of the H₂ molecule, Opt. Spectrosc. Engl. Transl., 1970, 29, 352, In original 658. [all data]

Kolos and Wolniewicz, 1974
Kolos, W.; Wolniewicz, L., Variational calculation of the long-range interaction between two ground-state hydrogen atoms, Chem. Phys. Lett., 1974, 24, 457. [all data]

Kolos and Wolniewicz, 1975, 2
Kolos, W.; Wolniewicz, L., Improved potential energy curve and vibrational energies for the electronic ground state of the hydrogen molecule, J. Mol. Spectrosc., 1975, 54, 303. [all data]

Waech and Bernstein, 1967
Waech, T.G.; Bernstein, R.B., Calculated spectrum of quasibound states for H₂(¹Σ_g⁺) and resonances in H + H scattering, J. Chem. Phys., 1967, 46, 4905. [all data]

Kolos and Wolniewicz, 1968, 2
Kolos, W.; Wolniewicz, L., Improved theoretical ground-state energy of the hydrogen molecule, J. Chem. Phys., 1968, 49, 404. [all data]

Allison, 1969
Allison, A.C., Quasi-bound states in H₂, Chem. Phys. Lett., 1969, 3, 371. [all data]

Herzberg and Mckenzie, 1979
Herzberg; Mckenzie, To be Published cited in Huber and Herzberg, 1979, 1979, 255. [all data]

Bunker, 1972
Bunker, P.R., On the breakdown of the Born-Oppenheimer approximation for a diatomic molecule, J. Mol. Spectrosc., 1972, 5, 478. [all data]

Orlikowski and Wolniewicz, 1974
Orlikowski, T.; Wolniewicz, L., Nonadiabatic corrections to the vibrational energies of the hydrogen molecule, Chem. Phys. Lett., 1974, 24, 461. [all data]

Dabrowski and Herzberg, 1976
Dabrowski, I.; Herzberg, G., The absorption and emission spectra of HD in the vacuum ultraviolet, Can. J. Phys., 1976, 54, 525. [all data]

Bishop and Shih, 1976
Bishop, D.M.; Shih, S.-K., An effective Schrodinger equation for the rovibronic energies of H₂ and D₂, J. Chem. Phys., 1976, 64, 162. [all data]

Buijs and Gush, 1971
Buijs, H.L.; Gush, H.P., Statis field induced spectrum of hydrogen, Can. J. Phys., 1971, 49, 2366. [all data]

Ramsey, 1952
Ramsey, N.F., Theory of molecular hydrogen and deuterium in magnetic fields, Phys. Rev., 1952, 85, 60. [all data]

Harney, Randolph, et al., 1975
Harney, R.C.; Randolph, J.E.; Milanovich, F.P., Relative Raman cross sections for the S(0) through S(4) rotational transitions in hydrogen, Astrophys. J., 1975, 200, 179. [all data]

Stwalley, 1970
Stwalley, W.C., The dissociation energy of the hydrogen molecule using long-range forces, Chem. Phys. Lett., 1970, 6, 241. [all data]

Bunker, 1979
Bunker, Unpublished cited in Huber and Herzberg, 1979, 1979, 255. [all data]

Hunter, 1966
Hunter, G., Adiabatic dissociation energies for the ground states of the H₂, HD, and D₂ molecules, J. Chem. Phys., 1966, 45, 3022. [all data]

Jeziorski and Kolos, 1969
Jeziorski, B.; Kolos, W., On the ionization potential of H₂, Chem. Phys. Lett., 1969, 3, 677. [all data]

Margolis, 1973
Margolis, J.S., Measurement of some 1-0 H₂ quadrupole transition strengths, J. Mol. Spectrosc., 1973, 48, 409. [all data]

McKellar, 1974
McKellar, A.R.W., The significance of pressure shifts for the interpretation of H₂ quadrupole lines in planetary spectra, Icarus, 1974, 22, 212. [all data]

Chackerian and Giver, 1975
Chackerian, C., Jr.; Giver, L.P., Density-dependent frequency shift of the hydrogen S₂(1) quadrupole line, J. Mol. Spectrosc., 1975, 58, 339. [all data]

James, 1969
James, T.C., Intensity of the quadrupole rotation-vibration spectrum of molecular hydrogen, J. Mol. Spectrosc., 1969, 32, 512. [all data]

Dalgarno and Wright, 1972
Dalgarno, A.; Wright, E.L., Infrared emissivities of H₂ and HD, Astrophys. J., 1972, 174, 49. [all data]

Black and Dalgarno, 1976
Black, J.H.; Dalgarno, A., Interstellar H₂: the population of excited rotational states and the infrared response to ultraviolet radiation, Astrophys. J., 1976, 203, 132. [all data]

Welsh, 1972
Welsh, H.L., Pressure-induced absorption spectra of hydrogen in MTP International Review of Science; Physical Chemistry, Series 1, Vol. 3, London, Butterworths, Baltimore, University Park Press, 1972, 33-71. [all data]

Huber and Herzberg, 1979
Huber, K.P.; Herzberg, G., Molecular Spectra and Molecular Structure. IV. Constants of Diatomic Molecules, Van Nostrand Reinhold Company, New York, 1979, 716. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Constants of diatomic molecules, References

• Symbols used in this document:
  

  S°gas,1 bar

  Entropy of gas at standard conditions (1 bar)

• 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.