FINITE-TEMPERATURE SIMULATION OF ABSORPTION SPECTRA IN SMALL ARGON-CLUSTER IONS ${\rm Ar}_n^ + $(n=3, 4, 8, 13, AND 19)

Abstract

We report finite-temperature simulations of the absorption spectra of argon-cluster ions using a diatomics in molecules (DIM) Hamiltonian (including spin-orbit coupling) for the determination of the potential-energy surfaces (PES), a point-charge approximation for the dipole transition moments and a Metropolis Monte-Carlo algorithm for the nuclear motion. The dependency of the absorption spectrum on cluster size (3≤n≤19) and on temperature (100 K≤T≤500 K) is analyzed.