This book, aimed at academics, industrialists and post-graduates, documents the latest research into computer aided drug design. It starts with the theory and application of force-fields including: semi-empirical molecular orbital; density functional and ab initio calculations; Quantum Mechanical (QM) based modelling; the Atoms in Molecules (AIM) approach, and biomolecular dynamics. It then goes on to focus on the theory and application of 2D cheminformatics. This encompasses QSAR/QSPR; ADME properties of drugs; drug docking/scoring protocols and approaches; topological methodology, and modelling accurate inhibition constants of enzymes. The final chapters describe the theory and applications of multiscale modelling of proteins and biomolecular systems.