Surface science has existed as a recognized discipline for more than 20 years. During this period, the subject has expanded in two important ways. On the one hand, the techniques available for studying surfaces, both experimental and theoretical, have grown in number and in sophistication. On the other hand, surface science has been applied to an increasing number of areas of technology, such as catalysis, semicon ductor processing, new materials development, corrosion prevention, adhesion and tribology. . There is, however, no sharp division between fundamental and applied surface science....