Constants of diatomic molecules

Go To: Top, References, Notes

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 May, 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 14N79Br
b 1Sigma+ 14787.3 785.5 H 4.363  0.4733 1 0.0152    1.7306 b rarrow X 2 V 14834.3 H
Elliott, 1939; missing citation
X 3Sigma-(0+) 0 3 691.75 H 4.720  0.444 3 1 0.0040 3    1.787 4  
Milligan and Jacox, 1964


1Potential functions Singh and Rai, 1966.
2Franck-Condon factors Itagi, Shamkuwar, et al., 1971.
3Only levels with N = J+1, i.e. F1(N) corresponding in case "c" to the 0+ component, have been observed at high resolution. For this reason, and since only B"3 and B"7 have been determined (assuming lambda ~8.7, gamma ~-0.7) the values of Be and alphae are not very precise.
4Vibration sp. 6
5Estimated from the highest v' value observed in brarrowX emission from the reaction N(4S) + Br(2P3/2) rarrow NBr* rarrow NBr + hv Milton, Dunford, et al., 1961.
6In argon and nitrogen matrices, DeltaG(1/2) = 691.


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.

Elliott, 1939
Elliott, A., A band spectrum attributed to NBr, Proc. R. Soc. London A, 1939, 169, 469. [all data]

Milligan and Jacox, 1964
Milligan, D.E.; Jacox, M.E., Infrared Spectra of NF, NCl, and NBr, J. Chem. Phys., 1964, 40, 9, 2461, . [all data]

Singh and Rai, 1966
Singh, R.B.; Rai, D.K., Potential curves for some diatomic molecules: P2, PN, SiN, NBr, BaO, BeF, SiF & SnF, Indian J. Pure Appl. Phys., 1966, 4, 102. [all data]

Itagi, Shamkuwar, et al., 1971
Itagi, S.; Shamkuwar, N.R.; Itagi, V.V., Franck-Condon factors for bands of NBr 1«SIGMA»+-3«SIGMA»- system, Indian J. Phys., 1971, 45, 385. [all data]

Milton, Dunford, et al., 1961
Milton, E.R.V.; Dunford, H.B.; Douglas, A.E., Spectrum of NBr excited in active nitrogen, J. Chem. Phys., 1961, 35, 1202. [all data]


Go To: Top, Constants of diatomic molecules, References