Polyatomic Molecules: Results of Ab Initio Calculations describes the symmetry of polyatomic molecules in ground states. This book contains 12 chapters that also cover the excited and ionized states of these molecules. The opening chapter describes the nature of the various ab initio computational methods. The subsequent four chapters deal with the three-atom systems, differing with respect to the number of hydrogen atoms in the molecules. These chapters also discuss the reaction surfaces of these systems. These topics are followed by discussions on the molecules whose ground states belong to relatively high, little or no symmetry groups. The concluding chapters explore the inorganic and relatively large organic molecules. These chapters also examine the ab initio calculations of molecular compounds and complexes, as well as hydrogen bonding and ion hydration. This text will be of great value to organic and inorganic chemists and physicists.