The theory of the chemical interaction of molecules with surfaces has advanced handsomely in the last few years. This is due in part to the application of the entire arsenal of bulk solid-state theory and molecular quantum chemistry methods. This considerable activity was stimulated by an outpouring of experimental data, particularly of photoemission spectra. In many cases the theoretical techniques are now such that accurate, atomistic pictures of chemisorption phenomena are computed from first principles. This level of capability has been reached only recently, and has not been described anywhere in a comprehensive manner. The purpose of this monograph is to review these recent advances and, at the same time, to indicate a number of important questions which have not been answered. We discuss chemisorption on oxides, semiconductors, and both simple and transition metals. Solid surfaces as well as clusters are considered. While the review should be valuable to workers in the field, care has been taken to make the chapters understandable to the nonspecialist.

1. Introduction..- 2. Density Functional Theory of Chemisorption on Simple Metals.- 2.1 Background Information.- 2.2 Statistical Approach.- 2.3 Approach Based on the Solution of Effective One-Electron Schrödinger Equation.- 2.4 Concluding Remarks.- References.- 3. Chemisorption on Semiconductor Surfaces.- 3.1 Background Information.- 3.2 Bulk Properties.- 3.3 General Surface Properties.- 3.4 Computational Approaches.- 3.5 Clean Semiconductor Surfaces.- 3.6 H Chemisorption on Si Surfaces.- 3.7 Cl Chemisorption on Si (111) and Ge(lll).- 3.8 Al Chemisorption on Si (111).- 3.9 Al Chemisorption on GaAs(llO).- References.- 4. Chemisorption on d-Band Metals.- 4.1 Moments Method.- 4.2 Muffin-Tin Methods.- 4.3 Parametrized LCA0 Methods.- 4.4 Linear Combination of Muffin-Tin Orbitals (LCMT0) Method.- 4.5 Self-Consistent Methods.- 4.6 Fully Self-Consistent Methods.- 4.7 Summary.- References.- 5. Cluster Chemisorption..- 5.1 Ideal Choice of Problem for Cluster Simulation.- 5.2 Methods of Obtaining a Solution.- 5.3 Interaction of Cluster and Environment.- 5.4 Examples of Cluster Calculations.- References.- 6. Concepts of Surface States and Chemisorption on d-Band Perovskites.- 6.1 Introductory Remarks.- 6.2 Cluster Models of Transition Metal Oxides.- 6.3 Bulk and Surface Electronic Properties of the Perovskites.- 6.4 Surface Oxygen Vacancy States (SOVS).- 6.5 Photoemission Experiments on SrTi03.- 6.6 Summary.- References.- 7. Theoretical Issues in Chemisorption.- 7.1 Local Density Approximations and Generalizations.- 7.2 The Anderson Model Picture.- 7.3 Beyond the Hartree-Fock Theory.- 7.4 Adatom-Adatom Interactions.- 7.5 Photoemission.- 7.6 Concluding Remarks.- References.