Xenon dimer

Constants of diatomic molecules

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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, 1977

Symbols used in the table of constants
SymbolMeaning
State electronic state and / or symmetry symbol
Te minimum electronic energy (cm-1)
ωe vibrational constant – first term (cm-1)
ωexe vibrational constant – second term (cm-1)
ωeye vibrational constant – third term (cm-1)
Be rotational constant in equilibrium position (cm-1)
αe rotational constant – first term (cm-1)
γe rotation-vibration interaction constant (cm-1)
De centrifugal distortion constant (cm-1)
βe rotational constant – first term, centrifugal force (cm-1)
re internuclear distance (Å)
Trans. observed transition(s) corresponding to electronic state
ν00 position of 0-0 band (units noted in table)
Diatomic constants for (129,132)Xe2
StateTeωeωexeωeyeBeαeγeDeβereTrans.ν00
Several emission bands and continua in the visible and near UV regions; interpretation and assignment to Xe2 uncertain.
↳Wilkinson and Tanaka, 1955; Roth and Gloersen, 1958
K 85139.6 26 1 1        K ← X 2 85141.9
↳Castex, 1974
Uncl. 4           3 
↳Castex, 1974; Freeman, Yoshino, et al., 1974
Uncl. 5           3 
↳Castex, 1974; Freeman, Yoshino, et al., 1974
StateTeωeωexeωeyeBeαeγeDeβereTrans.ν00
H 82001 [30.0] 6         H ← X 7 82005.7
↳Castex, 1974
Uncl.Unclassified abs. bands, associated with 5d[1 1/2]2o (80323.28 cm-1) 8
↳Herzberg, 1979; Castex, 1974; Keto, Gleason, et al., 1974
Unclassified abs. bands, associated with 6p[0 1/2]0 (80119.47 cm-1) 8
↳Herzberg, 1979; Castex, 1974; Keto, Gleason, et al., 1974
Uncl. 9           3 
↳Herzberg, 1979; Castex, 1974; Keto, Gleason, et al., 1974
Unclassified abs. bands, associated with 6p[1 1/2]2 (79212.97 cm-1) 8
↳Herzberg, 1979; Castex, 1974; Keto, Gleason, et al., 1974
Unclassified abs. bands, associated with 6p[1 1/2]1 (78956.54 cm-1) 8
↳Herzberg, 1979; Castex, 1974; Keto, Gleason, et al., 1974
StateTeωeωexeωeyeBeαeγeDeβereTrans.ν00
Uncl. 11           10 
↳Herzberg, 1979; Castex, 1974; Keto, Gleason, et al., 1974
Unclassified abs. bands, associated with 6p[2 1/2]2 (78120.30 cm-1) 8
↳Herzberg, 1979; Castex, 1974; Keto, Gleason, et al., 1974
Uncl. 13           12 
↳Castex and Damany, 1972
For the A and B states there are unclassified absorption bands longward and shortward of the resonance line at 68045.66 cm-1 (1469.6 Å); pressure broadening of this line due to molecule formation. Continuous emission 68000 - 50000 cm-1 (1470 - 2000 Å) with maxima near 68030, 67070 cm-1 (1470, 1491 Å, "first continuum") and ~58800 cm-1 (1700 Å, "second cont.")
StateTeωeωexeωeyeBeαeγeDeβereTrans.ν00
B (1Σu+) 0u+           B ↔ X 14 15 
↳McLennan and Turnbull, 1933; Tanaka and Zelikoff, 1954; missing citation; Tanaka, 1955; Huffman, Larrabee, et al., 1965; Wilkinson, 1966
A (3Σu+) 1u           A ↔ X 14 15 16 
X 1Σg+ 0 21.12 H 0.65 17 .003      4.361 18  

Notes

1Associated with 7s[1 1/2]2o (85189.31 cm-1) 8
2Several v" progressions (presumably v'=0...4) near 1174 Å.
3Bands longward of 1192 and 1250 Å have been partially analyzed by Castex, 1974, Freeman, Yoshino, et al., 1974; the ground state vibrational levels of Freeman, Yoshino, et al., 1974 are from this analysis.
4Unclassified absorption bands, associated with 5d[1 1/2]1o (83890.47 cm-1) 8
5Unclassified absorption bands, associated with 5d[2 1/2]3o (82430.72 cm-1) 8
6Associated with 5d[2 1/2]2o (81926.04 cm-1) 8
7Two v" progressions shortward, and two broad bands longward, of 1221 Å.
8Atomic energy levels relative to 5p6 1S.
9Unclassified abs. bands, associated with 5d[0 1/2]1o (79987.16 cm-1) 8
10 Chashchina and Shreider, 1976 have determined the oscillator strength (f = 0.039~ Chashchina and Shreider, 1976) for a band at 1274.8 Å.
11Unclassified abs. bands, associated with 6p[2 1/2]3 (78403.56 cm-1) 8
12Continuous absorption and ill-defined vibrational structure longward of 1296 Å; small number of sharp bands at shorter wavelengths.
13Unclassified abs. bands, associated with 6s'[0 1/2]1o (77185.56 cm-1) 8
14Radiative lifetimes; τ(A)= 100 ns Keto, Gleason, et al., 1974, Keto, Gleason, et al., 1976, Leichner, Palmer, et al., 1976 [theoretical value: τ= 23 ns Weihofen, 1974], τ(B)= 6 ns Keto, Gleason, et al., 1974, Keto, Gleason, et al., 1976, Leichner, Palmer, et al., 1976. A and B are associated with the lowest excited states of Xe I, i.e. 6s[1 1/2]o2 (67068.05 cm-1) and 6s[1 1/2]o1 (68045.66 cm-1), respectively.
15The continuum is observed in discharges at high pressure as well as in fluorescence excited by the Xe I 1470 Å resonance line Freeman, McEwan, et al., 1971, by CO fourth positive bands Fink and Comes, 1975, and by synchrotron radiation Brodmann, Zimmerer, et al., 1976. There is good evidence that the "first continuum" is due to vibrationally unrelaxed molecules in the A and B states, while the "second continuum" corresponds to transitions from v'~0 of these states to the steep repulsive part of the X 1Σg+ potential curve Mulliken, 1970, Mulliken, 1974. A broad emission peak at 1725 Å, probably representing the same transition, has been observed by bombardment of Xe in a Ne matrix with alpha particles Gedanken, Raz, et al., 1973.
16 Mulliken, 1974 estimates re ~ 3.25 Å Mulliken, 1974.
17Zero point energy 10.40 cm-1; last stable vibrational level (extrapolated) v=25 Freeman, Yoshino, et al., 1974.
18From bulk properties and differential scattering cross sections Barker, Watts, et al., 1974 [see Freeman, Yoshino, et al., 1974, "note added in proof"]; see also Docken and Schafer, 1973. Electron diffraction Audit, 1969 gives 4.41 Å.
19Spectroscopic value, by extrapolation from the observed lowest ten vibrational levels of the ground state Freeman, Yoshino, et al., 1974. The corresponding well depth is in very good agreement with De0 = 0.0243 eV Barker, Watts, et al., 1974 derived by Barker, Watts, et al., 1974 from bulk properties and differential scattering cross sections as well as spectroscopic data. Integral absorption measurements of the 1274.8 Å band (78444 cm-1) as a function of temperature give D00 = 0.029 eV Chashchina and Shreider, 1976.
20Photoionization of Xe2 Ng, Trevor, et al., 1976. An earlier determination based on the formation of Xe2+ from Rydberg excited Xe (associative ionization) yielded 11.14 eV Samson and Cairns, 1966.

References

Go To: Top, 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.

Wilkinson and Tanaka, 1955
Wilkinson, P.G.; Tanaka, Y., New xenon-light source for the vacuum ultraviolet, J. Opt. Soc. Am., 1955, 45, 344. [all data]

Roth and Gloersen, 1958
Roth, W.; Gloersen, P., Shock-tube study of luminosity in xenon, J. Chem. Phys., 1958, 29, 820. [all data]

Castex, 1974
Castex, M.-C., High resolution spectrum of the xenon molecule in the vacuum ultraviolet region (1150-1300 Å), Chem. Phys., 1974, 5, 448. [all data]

Freeman, Yoshino, et al., 1974
Freeman, D.E.; Yoshino, K.; Tanaka, Y., Vacuum ultraviolet absorption spectrum of the van der Waals molecule Xe2. I. Ground state vibrational structure, potential well depth and shape, J. Chem. Phys., 1974, 61, 4880. [all data]

Herzberg, 1979
Herzberg, Unpublished cited in Huber and Herzberg, 1979, 1979, 661. [all data]

Keto, Gleason, et al., 1974
Keto, J.W.; Gleason, R.E., Jr.; Walters, G.K., Production mechanisms and radiative lifetimes of argon and xenon molecules emitting in the ultraviolet, Phys. Rev. Lett., 1974, 33, 1365. [all data]

Castex and Damany, 1972
Castex, M.-C.; Damany, N., Absorption spectrum of the xenon molecule in the vacuum ultraviolet region, Chem. Phys. Lett., 1972, 13, 158. [all data]

McLennan and Turnbull, 1933
McLennan, J.C.; Turnbull, R., The broadening of the ultraviolet absorption bands of xenon under pressure, Proc. R. Soc. London A, 1933, 139, 683. [all data]

Tanaka and Zelikoff, 1954
Tanaka, Y.; Zelikoff, M., Continuous emission spectrum of xenon in the vacuum ultraviolet region, J. Opt. Soc. Am., 1954, 44, 254. [all data]

Tanaka, 1955
Tanaka, Y., Continuous emission spectra of rare gases in the vacuum ultraviolet region, J. Opt. Soc. Am., 1955, 45, 710. [all data]

Huffman, Larrabee, et al., 1965
Huffman, R.E.; Larrabee, J.C.; Tanaka, Y., Rare gas continuum light sources for photoelectric scanning in the vacuum ultraviolet, Appl. Opt., 1965, 4, 1581. [all data]

Wilkinson, 1966
Wilkinson, P.G., Oscillator strengths of the resonance lines of the rare gases. II. Xenon, J. Quant. Spectrosc. Radiat. Transfer, 1966, 6, 823. [all data]

Chashchina and Shreider, 1976
Chashchina, G.I.; Shreider, E.Ya., Absorption bands of krypton and xenon molecules near the forbidden lines, J. Appl. Spectrosc. Engl. Transl., 1976, 25, 922, In original 163. [all data]

Keto, Gleason, et al., 1976
Keto, J.W.; Gleason, R.E., Jr.; Bonifield, T.D.; Walters, G.K.; Soley, F.K., Collisional mixing of the lowest bound molecular states in xenon and argon, Chem. Phys. Lett., 1976, 42, 125. [all data]

Leichner, Palmer, et al., 1976
Leichner, P.K.; Palmer, K.F.; Cook, J.D.; Thieneman, M., Two- and three-body collision coefficients for Xe(3P1) and Xe(3P2) atoms and radiative lifetime of the Xe2(1u) molecule, Phys. Rev. A: Gen. Phys., 1976, 13, 1787. [all data]

Weihofen, 1974
Weihofen, W.H., Spontaneous decay of the "3Σu+" state of Xe2, J. Chem. Phys., 1974, 60, 445. [all data]

Freeman, McEwan, et al., 1971
Freeman, C.G.; McEwan, M.J.; Claridge, R.F.C.; Phillips, L.F., Band fluorescence of xenon, Chem. Phys. Lett., 1971, 10, 530. [all data]

Fink and Comes, 1975
Fink, E.H.; Comes, F.J., Fluorescence of Xe2 molecules in the vacuum-ultraviolet, Chem. Phys. Lett., 1975, 30, 267. [all data]

Brodmann, Zimmerer, et al., 1976
Brodmann, R.; Zimmerer, G.; Hahn, U., Investigation of the vacuum ultraviolet fluorescence of gaseous xenon under optical excitation in an extended wavelength region, Chem. Phys. Lett., 1976, 41, 160. [all data]

Mulliken, 1970
Mulliken, R.S., Potential curves of diatomic rare-gas molecules and their ions, with particular reference to Xe2, J. Chem. Phys., 1970, 52, 5170. [all data]

Mulliken, 1974
Mulliken, R.S., Potential energy curves and radiative transition probabilities for rare-gas molecules, Radiat. Res., 1974, 59, 357. [all data]

Gedanken, Raz, et al., 1973
Gedanken, A.; Raz, B.; Jortner, J., Emission spectra of homonuclear diatomic rare gas molecules in solid neon, J. Chem. Phys., 1973, 59, 1630. [all data]

Barker, Watts, et al., 1974
Barker, J.A.; Watts, R.O.; Lee, J.K.; Schafer, T.P.; Lee, Y.T., Interatomic potentials for krypton and xenon, J. Chem. Phys., 1974, 61, 3081. [all data]

Docken and Schafer, 1973
Docken, K.K.; Schafer, T.P., Spectroscopic information on ground-state Ar2, Kr2, and Xe2 from interatomic potentials, J. Mol. Spectrosc., 1973, 46, 454. [all data]

Audit, 1969
Audit, P., Liaisons intermoleculaires dans les jets supersoniques etude par diffraction d'electrons, J. Phys. (Paris), 1969, 30, 192. [all data]

Ng, Trevor, et al., 1976
Ng, C.Y.; Trevor, J.; Mahan, B.H.; Lee, Y.T., Photoionization study of the Xe2 van der Waals molecule, J. Chem. Phys., 1976, 65, 4327. [all data]

Samson and Cairns, 1966
Samson, J.A.R.; Cairns, R.B., Ionization potential of molecular xenon and krypton, J. Opt. Soc. Am., 1966, 56, 1140. [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

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