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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 June, 1976

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 (79,81)Br2-
(2Pig)1/2 [77500] 363 1          
missing citation
(2Pig)3/2 [74700]           
missing citation
X (2Sigmau+) [0]           


1From two progressions of resonances in the scattering of electrons by Br2 indicating the existence of a preionized doubly excited state of Br2- with the X 2Pig state of Br2+ as "grandparent" Spence, 1974.
2D00(Br2) + I.P.(Br2-) - I.P.(Br-).
3From endoergic charge transfer Chupka, Berkowitz, et al., 1971, Baeda, 1972, Hughes, Lifschitz, et al., 1973, Tang, Leffert, et al., 1975. Dissociative electron attachment gives the slightly higher value of 2.87 eV DeCorpo and Franklin, 1971.


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

Spence, 1974
Spence, D., Systematics of Feshbach resonances in the molecular halogens, Phys. Rev. A: Gen. Phys., 1974, 10, 1045. [all data]

Chupka, Berkowitz, et al., 1971
Chupka, W.A.; Berkowitz, J.; Gutman, D., Electron Affinities of Halogen Diatomic Molecules as Determined by Endoergic Charge Exchange, J. Chem. Phys., 1971, 55, 6, 2724, https://doi.org/10.1063/1.1676487 . [all data]

Baeda, 1972
Baeda, A.P.M., The adiabatic electron affinities of Cl2, Br2, I2, IBr, NO2, and O2, Physica, 1972, 59, 541. [all data]

Hughes, Lifschitz, et al., 1973
Hughes, B.M.; Lifschitz, C.; Tiernan, T.O., Electron affinities from endothermic negative-ion charge-transfer reactions. III. NO, NO2, S2, CS2, Cl2, Br2, I2, and C2H, J. Chem. Phys., 1973, 59, 3162. [all data]

Tang, Leffert, et al., 1975
Tang, S.Y.; Leffert, C.B.; Rothe, E.W., Ionizing collisions of cesium with Cl2, Br2, and I2, J. Chem. Phys., 1975, 62, 132. [all data]

DeCorpo and Franklin, 1971
DeCorpo, J.J.; Franklin, J.L., Electron affinities of the halogen molecules by dissociative electron attachment, J. Chem. Phys., 1971, 54, 1885. [all data]


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