Computer modelling of chemical systems is nowadays a well established sub ect, sufficiently mature and reliable to be helpful to the experimentalist and to attract the interest of commercial software manufactures. This book collects selected contributions in quantum and in statistical chemistry, the oldest and classical branches of this sub ect, where our present understanding of the chemical phenomena relies on.

Startin from the quantum mechanical calculation of the properties of sing e molecules, isolated and interacting with radiation, going through the reaction dynamics, we are led to the computer simulation of equilibrium and non equilibrium macroscopic systems. More than a comprehensive overview of the field, this book offers state-of-the-art presentations of particular aspects, problems, methods, applications, resulting from the experience of a number of researchers involved in the "Progetto Finalizzato Sistemi Informatici e Calcolo Parallelo" sponsored by the Italian National Research Council.

Gian Luigi Bendazzoli is a Full Professor of Chemical Physics at the University of Bologna. His main research interest is about teorethic Chemistry.

Paolo Palmieri is Full Professor of Chemical Physics at the University of Bologna. He developped and is developping his research activity in other universities too: Sheffield, Cambridge, Paris, Frankfurt, Copenaghen.