Genetic based fitting techniques for high precision potential energy curves of diatomic molecules

We present development of a genetic algorithm for fitting potential energy curves of diatomic molecules to experimental data. Our approach does not involve any functional form for fitting, which makes it a general fitting procedure. In particular, it takes in a ‘trial’ potential, along with experimental measurements of vibrational binding energies, rotational constants, and their experimental uncertainties. The fitting procedure is able to converge to better than 1% uncertainty, as measured by χ ¯ 2 or reproduce the experimental data to better than 0.03 cm −1 . We present the details of this technique for the X 1 Σ + of lithium–rubidium.