Analysis of the long range potential of 79Br2 in the B 3+0u state and molecular constants of the three isotopic bromine species 79Br2, 79,81Br2 and 81Br2

2014 The analysis of the outer branch of the potential of the B 303A0+0u state of the bromine molecule 79Br2 was carried out by means of the multipole expansion of the interaction energies truncated up to the C 10/R10v term, the exchange energy Vex (R) being neglected and the hyperfine effects ignored. The value of the dissociation limit De and the values of the Cn coefficients are not dependent on the number of turning points considered. The vibrational energies and the rotational constants of the isotopic species 79,81Br2 and 81Br2 were calculated according to the classical isotopic relations, the constants of 79Br2 being known. Relative to the ground level X 103A3+g (v = 0, J = 0), the dissociation limit D’0 of the B state belonging to 79Br2 was found to be equal to 19 579.692 (10) cm-1, while the values of D"e, D’e and Te, e were found to be equal to 3 839.592 (8), 16 056.926 (14) and 15 902.480 (6) cm-1 respectively. High order Centrifugal Distortion Constants (Dv, Hv, Lv, Mv) were calculated using the perturbation method and, finally, a set of molecular constants, which enables to recalculate a priori the absorption spectrum of natural bromine corresponding to the (B 303A0+0u ~ X 103A3+g) system is presented. J. Phys. France 50 (1989) 1417-1432 15 JUIN 1989, Classification Physics Abstracts 33.20K 31.90 (*) Laboratoire associé à l’Université Paris-Sud. Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphys:0198900500120141700