Preface. Surface Crystallography: The Experimental Data Base (P.J. Rous). Abstract. Introduction. Metals. Semiconductors. Graphite and diamond surfaces. Compounds. Selected bibliography. Acknowledgements. References. Theory of Surface Structure and Bonding (J.E. Inglesfield). Abstract. Introduction. Solving the Schroedinger equation at the surface. Forces and optimization. Clean metal surfaces. Adsorbates on metals. Semiconductor surfaces. Conclusions. Acknowledgements. References. Phase Transitions at Surfaces (K. Binder). Abstract. Introduction: surface phase transitions versus transitions in the bulk. Phenomenological theory of phase transitions: a brief review. Surface effects on bulk phase transitions. Discussion. Acknowledgements. References. Surface Structure and Reactivity (M. Bowker). Abstract. Introduction. Thermodynamic considerations. Adsorption. Desorption. Surface diffusion. Surface reactions. Structure dependence of reactivity. Modification of surface reactivity: poisoning and promotion. Conclusions. References. Author index. Subject index.