<P>This important new edition is for graduate students studying Molecular Modelling, Computational Chemistry within Chemistry,  Medicinal Chemistry and Biochemistry.   Postgraduates and researchers in academia and in the chemical and pharmaceutical industries. This new edition introduces background theory and techniques of molecular modelling, also illustrates applications in studying physical, chemical and biological phenomena.  It includes simple numerical examples and numerous explanatory figures and a colour plate section.  <BR></P>