A concise, basic introduction to modelling and computational chemistry which focuses on the essentials, including MM, MC, and MD, along with a chapter devoted to QSAR and Discovery Chemistry. Includes supporting website featuring background information, full colour illustrations, questions and answers tied into the text, Visual Basic packages and many realistic examples with solutions Takes a hands-on approach, using state of the art software packages G03/W and/or Hyperchem, Gaussian . gjf files and sample outputs. Revised with changes in emphasis and presentation to appeal to the modern student.