The methods of computational chemistry are being expanded and improved in this study in the Theoretical and Computational Chemistry Program in the Division of Chemistry in order to permit their greater applicability to very large molecular systems including surfaces and other bulk forms of matter. New methods patterned after electron density functional theory are being developed. Applications include the modeling of chemisorption of metal atoms to graphite surfaces, the interpretation of scanning tunneling microscopy (STM) images, and studies of the epitaxial growth of diamond. The work also involves the large-area (global) networking of supercomputers. %%% New mathematical and computational models are being developed to permit the calculation of the properties of very molecular systems including the bonding of metal atoms to graphite surfaces and the growth of diamond crystals. An important aspect of this work is its use of large-area (global) networking of supercomputers.