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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 January, 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 115In(79)Br+
B (2Sigma) (26500) 1           
A (2Pi) 4300 0 1           
X (2Sigma) 0 1           


1From the photoelectron spectrum (adiabatic potentials) Berkowitz and Dehmer, 1972. 9
2From thermochemical data and spectroscopic evidence about the 1Pi and 3Pi excited states; see Barrow, 1960. in good agreement with 4.02 eV obtained by flame photometry Bulewicz, Phillips, et al., 1961.
3Adiabatic potential from the photoelectron spectrum Berkowitz and Dehmer, 1972; vertical potential 9.41 eV.
4Vertical transition from v" = 0.
5Constants for 115In79Br are given by Lakshminarayana and Harnath, 1970, who propose small changes in the vibrational numbering of the B-X bands observed by Wehrli and Miescher, 1933.
6Calculated from the rotational constants for the 115In79Br isotope Barrett and Mandel, 1958.
7Electric quadrupole coupling constants.
8From D00(InBr) + I.P.(In) - I.P.(InBr).
9The 2Pi photoelectron peak is very broad with a maximum at 10.20 eV (2Pi1/2?), and a shoulder at ~ 9.8 eV (2Pi3/2?). These vertical potentials are close to the dissociation limits In+(1S) + Br(2P1/2, 2Pi3/2) at 10.24 and 9.78 eV, respectively, and seem compatible with the predicted instability or near instability of A 2Pi.


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

Berkowitz and Dehmer, 1972
Berkowitz, J.; Dehmer, J.L., Photoelectron spectroscopy of high-temperature vapors. II. Chemical bonding in the Group III monohalides, J. Chem. Phys., 1972, 57, 3194. [all data]

Barrow, 1960
Barrow, R.F., Dissociation energies of the gaseous monohalides of boron, aluminium, gallium, indium, and thallium, Trans. Faraday Soc., 1960, 56, 952. [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]

Lakshminarayana and Harnath, 1970
Lakshminarayana, A.; Harnath, P.B.V., The emission spectrum of indium monobromide, Indian J. Phys., 1970, 44, 504. [all data]

Wehrli and Miescher, 1933
Wehrli, M.; Miescher, E., Die spektren der indiumhalogenide, Helv. Phys. Acta, 1933, 6, 457. [all data]

Barrett and Mandel, 1958
Barrett, A.H.; Mandel, M., Microwave spectra of the Tl, In, and Ga monohalides, Phys. Rev., 1958, 109, 1572. [all data]


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