Modern quantum chemical methods can be
used to investigate many properties of novel molecules and materials with
predictive power. We have carried out accurate quantum chemical calculations
with cluster models to investigate chemical reactions on semiconductor surfaces.
The structure-property relationships that emerge from these studies are illustrated
with particular emphasis on silicon as well as indium phosphide surface chemistry.
Some new strategies that we have developed to provide a proper balance between
covalent and dative bonding in compound semiconductors will be discussed.
This talk will present several recent examples from our structural and mechanistic
studies focusing on understanding surface chemical processes. Unusual structural
species are identified in many cases and our results are used to provide
novel interpretations of experimental spectroscopic data.