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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 March, 1977

Symbols used in the table of constants
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 23Na(79)Br+
A (1/2) 5240 1 2           
X (3/2,1/2) 0 1 2           


1From band maxima in the photoelectron spectrum Goodman, Allen, et al., 1974, Potts, Williams, et al., 1974.
2Removal of an electron from the halogen 4p shell of Na+ Br-.
3Thermochemical value [ Brewer and Brackett, 1961, Stull and Prophet, 1971; flame photometry, Bulewicz, Phillips, et al., 1961].
4Onset of a broad photoelectron peak with maximum at 8.80 eV, not corrected for thermal population of ground state levels Potts, Williams, et al., 1974. See also Goodman, Allen, et al., 1974.
5UV absorption cross sections Davidovits and Brodhead, 1967; Absorption at higher energies produces fluorescence from Na (3p 2P), maximum efficiency at 50500 cm-1 Earl and Herm, 1974.
6The absorption spectrum of NaBr trapped in inert gas matrices shows band structure at v > 32300 cm-1; under certain conditions as many as 16 peaks have been observed with spacings of approximately 453 and 523 cm-1 in Ar, 529 in Kr, and 472 in N2 Oppenheimer and Berry, 1971.
7From the IR spectrum Rice and Klemperer, 1957; omegae = 298.49 Rice and Klemperer, 1957 and omegaexe = 1.16 Rice and Klemperer, 1957 have been calculated by Rusk and Gordy, 1962 from the microwave results using Dunham's theory.
8muel[D] = 9.0918 + 0.0531(v + 1/2), v leq 2 Hebert, Lovas, et al., 1968. Melendres, 1968, quoted in Miller, Finney, et al., 1973, gives eqQ values and their dependence on v.
9From D00(NaBr) + I.P.(Na) - I.P.(NaBr). Potts, Williams, et al., 1974 give 0.49 eV using a corrected value of I.P.(NaBr).


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

Goodman, Allen, et al., 1974
Goodman, T.D.; Allen, J.D., Jr.; Cusachs, L.C.; Schweitzer, G.K., The photoelectron spectra of gaseous alkali halides, J. Electron Spectrosc. Relat. Phenom., 1974, 3, 289. [all data]

Potts, Williams, et al., 1974
Potts, A.W.; Williams, T.A.; Price, W.C., Photoelectron spectra and electronic structure of diatomic alkali halides, Proc. Roy. Soc. London A, 1974, 341, 147. [all data]

Brewer and Brackett, 1961
Brewer, L.; Brackett, E., The dissociation energies of gaseous alkali halides, Chem. Rev., 1961, 61, 425. [all data]

Stull and Prophet, 1971
Stull, D.R.; Prophet, H., JANAF Thermochemical Tables. Second Edition, Office of SRD (NSRDS-NBS 37), Washington, D.C., 1971, 0. [all data]

Bulewicz, Phillips, et al., 1961
Bulewicz, E.M.; Phillips, L.F.; Sugden, T.M., Determination of dissociation constants and heats of formation of simple molecules by flame photometry. Part 8. Stabilities of the gaseous diatomic halides of certain metals, Trans. Faraday Soc., 1961, 57, 921. [all data]

Davidovits and Brodhead, 1967
Davidovits, P.; Brodhead, D.C., Ultraviolet absorption cross sections for the alkali halide vapors, J. Chem. Phys., 1967, 46, 2968. [all data]

Earl and Herm, 1974
Earl, B.L.; Herm, R.R., Photodissociation of NaBr, Nal, and Kl vapors and collisional quenching of Na* (32P), K* (42P), and K* (52P) by foreign gases, J. Chem. Phys., 1974, 60, 4568. [all data]

Oppenheimer and Berry, 1971
Oppenheimer, M.; Berry, R.S., Ultraviolet spectra of alkali halides in inert matrices, J. Chem. Phys., 1971, 54, 5058. [all data]

Rice and Klemperer, 1957
Rice, S.A.; Klemperer, W., Spectra of the alkali halides. II. The infrared spectra of the sodium and potassium halides, RbCl, and CsCl, J. Chem. Phys., 1957, 27, 573. [all data]

Rusk and Gordy, 1962
Rusk, J.R.; Gordy, W., Millimeter wave molecular beam spectroscopy: alkali bromides and iodides, Phys. Rev., 1962, 127, 817. [all data]

Hebert, Lovas, et al., 1968
Hebert, A.J.; Lovas, F.J.; Melendres, C.A.; Hollowell, C.D.; Story, T.L., Jr.; Street, K., Jr., Dipole moments of some alkali halide molecules by the molecular beam electric resonance method, J. Chem. Phys., 1968, 48, 2824. [all data]

Melendres, 1968
Melendres, Thesis, University of California, California, 1968, 1. [all data]

Miller, Finney, et al., 1973
Miller, C.E.; Finney, A.A.; Inman, F.W., Rotational and hyperfine structure constants for groups IA and IIIA monohalide and monohydride molecules, At. Data, 1973, 5, 1. [all data]


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