Theory of charge transfer at surfaces and interfaces

Surfaces and interfaces are important for both science and technology. Stimulated and challenged by sophisticated experimental techniques applied to their study on well prepared and characterized materials, theory - especially local density electronic structure theory - has responded in what may be called a dramatic fashion. This paper describes some aspects of the present state of self-consistent all-electron local density theory for treating surfaces, interfaces and overlayers. Following a review of the methodology, results of detailed calculations on representative specific systems are presented which illustrate the important role of charge transfer; the understanding acquired from these studies will be described and discussed.