Electronic energy shifts of a sodium atom in argon clusters by simulated annealing

Abstract

Born–Oppenheimer electronic surfaces for NaArn clusters are calculated using simulated annealing with a floating Gaussian basis set. The electronic energy levels are obtained during a molecular dynamics simulation of nuclear motion. Classical dynamics is used to search for local minima of the cluster potential energy surface. Results are presented for NaArn, n=1, 2, 3, 4, and for two large clusters, NaAr20 and NaAr24. Predictions of vertical transition energies of the cluster solvated sodium atom are given. The blueshifted transition frequencies for NaAr20 and NaAr24, clusters in which the metal atom is densely surrounded by rare gas solvent, are comparable to the largest sodium blueshifts observed in argon matrix spectra.