Date of Award

Spring 1997

Project Type


Program or Major


Degree Name

Doctor of Philosophy

First Advisor

J J Wright


A computer simulation of the formation of trapping sites for sodium atoms trapped in a solid argon matrix has been performed, using experimentally determined argon-argon and sodium-argon potentials available in the literature. The simulation method is a greatly simplified version of the more time-consuming molecular dynamics approach. Optical absorption and emission spectra corresponding to the matrix-perturbed 3s-3p sodium transition were calculated for each simulated trapping site, using first-order perturbation theory and the available sodium-argon dimer potentials. Two of the three requisite sodium-argon dimer potentials, the X$\sp2\Sigma$ and the A$\sp2\Pi,$ have been determined experimentally, but for the B$\sp2\Sigma$ potential, only a theoretical calculation is available. The computer simulation produced only one type of trapping site, and a simple, one-parameter adjustment of the theoretical B$\sp2\Sigma$ potential brought the calculated absorption and emission spectra into good agreement with the absorption and emission observed for the dominant, thermally stable trapping site produced in experiments. This agreement was unique, in the sense that no adjustment of the B$\sp2\Sigma$ potential could reproduce the observed absorption and emission spectra for the relatively unstable or less probable trapping site formed in experiments.