Computer simulation of interfaces: What do we need to know?

We analyze some of the key challenges in the computer simulation of interfaces. These fall into three main groups. First, there are challenges associated with charge on insulator surfaces, including charge patches, charge transfer processes, and charges associated with specific defects. These charges are important in phenomena such as sensor action, in tribology and, especially through tribocharging, in safety issues. Secondly, there are problems in epitaxy. Many of the key issues are understood, of course, but both experiment and computer modelling are showing new Features. An example is the memory of epitaxy through an amorphous intermediate layer. Thirdly, there are issues concerned with interatomic potentials. In certain cases, following electronic excitation, one cannot always use a potential of the standard sort. However, even for ground state problems, some results are extremely sensitive to details, and especially to the weak long-range terms which are usually regarded as a minor detail. We discuss specifically the growth modes of metals on oxide and halide surfaces. (C) 1998 Acta Metallurgica Inc.