Over the past few years, there has been a growing awareness of the vibratio nal properties of solid surfaces and adsorbates due to a steady growth in the number of experimental techniques which have evolved with sufficient resolution and surface sensitivity. An understanding of the surface vibratio nal modes is of fundamental importance in many areas of the physics and chemistry of surfaces, most notably in the field of heterogeneous catalysis on metals and alloys. The present volume derives from a one day meeting of invited lectures, held under the auspices of the Thin Films and Surfaces...