DESCRIPTION: (Adapted from Applicant's Abstract) Recent developments in the research groups of R. Friesner (University of Texas) and W. Goddard (Caltech) have led to the development of the pseudospectral generalized valence bond (PSGVB) electronic structure method, which has the potential to decrease by several orders of magnitude the costs of accurate ab initio quantum chemical calculations of structure, charges, bond energies, force fields, and excitation energies for large molecules. This methodology allows accurate Hartree-Fock calculations for systems as large as 200 atoms, while GVB and many-body perturbation theory computations on systems 1/2 to 1/3 this size will be feasible. This Phase I SBIR proposal is to develop a graphical user interface and associated input data structures needed for experimental biomedical researchers to utilize these breakthroughs. The interface will allow users to draw molecules of interest at a workstation, select the required chemical accuracy and properties to be computed, and then turn control over to an automated system of programs. The Phase I version of the program will be able to carry out charge calculations and geometry optimizations for large systems at the Hartree-Fock and GVB-perfect pairing (GVB-PP) levels. In Phase II, other properties and higher correlation levels will be implemented.