Surface physics has experienced in the last two decades anexplosive expansion caused by the development and/orsubstantial improvement of surface sensitive techniques andUHV apparatuses. It has grown into a maturefield ofresearch, with data of the highest accuracy andreproducibility. Surface physics is of great importance fortechnological applications like field effect devices,molecular beamepitaxy, chemisorption and catalysis,corrosion, surface hardening etc.The present volume III/24 is restricted to the so called"clean" surfaces, i.e. to surfaces atomically clean and wellcharacterized, leaving the more complex field of thecontaminated surfaces and overlayers to a later occasion.Due to the large amount of data this volume is divided intofour subvolumes: III/24a, b, c, d (see below). Each chapterconsists of an introduction giving a brief presentation ofthe subject and a data section in form of tables, figures,and pictures.A general index in which all data are ordered alphybeticallyaccording to the material and to the surface is given at theend of subvolume III/24d.