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

The techniques of generalized simulated annealing are here presented in a way to fit the external turning points of a diatomic molecule potential energy curve. In order to evaluate the advantages of this method the long-range part of the potential energy curve for the A 1Σ+u electronic state of the 6Li2 molecule is treated using the multipolar expansion and the asymptotic exchange energy considering the gradual change from a Hundʹs case a towards Hundʹs case c. The results are carefully compared with previous determinations using conventional fitting methods of molecular spectroscopy.