The state-of-the-art theoretical studies of ground state properties, electronic states and atomic vibrations for bulk semiconductors and their surfaces by the application of the pseudopotential method are discussed. Studies of bulk and surface phonon modes have been extended by the application of the phenomenological bond charge model. The coverage of the material, especially of the rapidly growing and technologically important topics of surface reconstruction and chemisorbtion, is up-to-date and beyond what is currently avaiable in book form. Although theoretical in nature, the book provides a good deal of discussion of available experimental results. Each chapter provides an adequate number of references, relevant for both theoretical and experimental studies. The presentation is coherent and self-contained, and is aimed at the postgraduate and postdoctoral level.