Professor Cioslowski of Florida State University is being supported by the Theoretical and Computational Chemistry program. During the next three years his group will cary out a comprehensive research program that aims at gaining theoretical knowledge of the electron-electron interactions in molecules will be carried out. The program will involve a suite of five innovative approaches to efficient computation, accurate approximation, and detailed analysis of the electron pair density and related two-electron quantities. High-performancealgorithms for the evaluation of the electron intracule and extracule densities on arbitrary grids of points will be developed. New applications of the Hiller-Sucher-Feinberg identity will afford accurate electron intracule densities that possess proper coalescence cusps at the origin, opening an avenue to fully non-empirical correlation energy functionals of the one-electron density matrix. Topological analysis of various components of the intracule and extracule densities will provide intriguing insights into electron correlation in molecules, whereas partitioning of two-electron properties will elucidate the relative importance of intra and interatomic correlation effects. A new approach to assembling the correlation holes from approximately transferable contributions will yield highly accurate density functionals for the correlation energy. The planned research will result in new approaches to computing properties of large molecules that are of importance to diverse branches of chemistry. The introduction of new correlation energy functionals will allow such computations to be carried out more rapidly and accurately, making it possible to study electronic structures of an ever-increasing number of chemical species. Consequently, first-principle modeling of biochemical systems, new pharmaceuticals, and advanced materials will become more feasible than ever before.
