Surface crystallography is a discipline which has come of age. There exist in the literature several hundred complete determinations of atomic configurations at surfaces: yet the number is not so great that cataloguing these structures is too daunting a task. We felt that now was the right moment to begin a compilation that could be updated at frequent intervals to give a comprehensive picture of the known surface world. The following pages are the product of our labours. Our target community is the large number of surface chemists, materials scientists, physicists and others whose work...