The Theoretical and Computational Chemistry Program of the Chemistry Division is supporting a research project by Kenneth Jordan in which he is investigating the properties of small ionized clusters. The work places special emphasis on problems of charge localization in clusters, the characterization of temporary anions of clusters, the interaction between weakly coupled chromophores, and the computer simulation of cluster properties. Effort is divided between the development and refinement of new techniques and use of the methods in applications to chemically important systems. The sphere approach used for stabilization calculations on temporary anions is being pursued and effort made to improve the efficiency of the jump-walk/multiple histogram method for Monte Carlo simulations. The latter is to be used to study "solid-liquid" melting transitions in small water clusters. %%% Theoretical chemists have made great progress in understanding and predicting the properties of matter in the gas phase, but have much more difficulty with solids. One approach to the problem is to examine small clusters of molecules in which the intermolecular forces responsible for holding a solid together are manifested in a system with a relatively small number of particles. This project is developing computational methods for investigating such clusters, with special emphasis on electrically charged clusters.