Generalized simulated annealing method in the analysis of atom-atom interaction

The techniques of generalized simulated annealing are here presented in a w ay to fit the external turning points of a diatomic molecule potential ener gy curve. In order to evaluate the advantages of this method the long-range part of the potential energy curve for the A(1)Sigma(u)(+) electronic stat e of the Li-6(2) molecule is treated using the multipolar expansion and the asymptotic exchange energy considering the gradual change from a Hund's ca se a towards Hund's case c. The results are carefully compared with previou s determinations using conventional fitting methods of molecular spectrosco py. (C) 1999 Elsevier Science B.V. All rights reserved.