In an attempt to introduce practical chemists, experimental researchers and students to chemical structure and energy calculations, the ability to determine the structure, stability, and other properties of an unknown molecule without synthesizing it opens up new chemical possibilities and turns fantasy molecules into accessible research objects. Although no training in theoretical chemistry is needed, the book does assume an adequate knowledge of symmetry operations and point groups, which are used throughout without further explanation. In both the molecular mechanics and Molecular Orbital (M0) sections, the emphasis is on the practical aspects of performing useful calculations and understanding the output.