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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 September, 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 74Ge35Cl
(D) 1           (D larrow X) 46640 H
Oldershaw and Robinson, 1970
(D)           (D larrow X) 47586 H
Oldershaw and Robinson, 1970
C (2Pi) 45845 493.4 H 2.0        C larrow X V 44914 H
missing citation
45824 493.4 H 2.0        C larrow X V 45867 H
missing citation
C' 42181 506.9 H 3.7        C' larrow X V 42230 H
missing citation
B (2Sigma) 33992.2 526.6 2 H (0.3)  3      B lrarrow X V 33078.0 H
missing citation; Barrow and Lagerqvist, 1949; Filippova and Kuzyakov, 1968
           B lrarrow X V 34052.0 H
missing citation
A' (2Deltar) 29561.7 335.5 H 4.58        A' rarrow X 4 R 28550.9 H
missing citation
29499.8 342.1 H 4.65        A' rarrow X 4 R 29466.2 H
missing citation
A (2Sigma+) 5           A rarrow X R 
Deschamps, Robert, et al., 1968; Rao and Haranath, 1969
X 2Pir 975.0 405.5 H 1.23  3       
0 407.6 H 1.36         


1Tentative assignments of bands above 46000 cm-1.
2 Filippova and Kuzyakov, 1968 and Mishra and Khanna, 1970 give slightly different constants.
3Partial rotational analysis of two subbands Mishra and Khanna, 1970.
4The bands have at least two heads of comparable intensity.
5Bands in the region 16000 - 25000 cm-1. Different vibrational analyses, omegae' ~ 250 cm-1.
6Extrapolation of vibrational levels in A'; atomic products at the limit uncertain.


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.

Oldershaw and Robinson, 1970
Oldershaw, G.A.; Robinson, K., Ultra-violet absorption spectrum of germanium monochloride, Trans. Faraday Soc., 1970, 66, 532. [all data]

Barrow and Lagerqvist, 1949
Barrow, R.; Lagerqvist, A., A new ultra-violet band-system of GeCl, Ark. Fys., 1949, 1, 221. [all data]

Filippova and Kuzyakov, 1968
Filippova, A.P.; Kuzyakov, Yu.Ya., Analysis of the vibrational structure of the 2«SIGMA» - 2«PI» system in GeCl, Moscow Univ. Chem. Bull. Engl. Transl., 1968, 23, 15, In original 25. [all data]

Deschamps, Robert, et al., 1968
Deschamps, P.; Robert, A.-F.; Pannetier, G., Observation et analyse vibrationnelle d'un nouveau systeme de bandes du monochlorure de germanium: A2«SIGMA»+-X2«PI», J. Chim. Phys. Phys.-Chim. Biol., 1968, 65, 1084. [all data]

Rao and Haranath, 1969
Rao, K.B.; Haranath, P.B.V., Emission band spectrum of GeCl in the visible region, J. Phys. B:, 1969, 2, 1080. [all data]

Mishra and Khanna, 1970
Mishra, R.K.; Khanna, B.N., The B-X band system of the GeCl molecule, Indian J. Pure Appl. Phys., 1970, 8, 825. [all data]


Go To: Top, Constants of diatomic molecules, References