This undergraduate textbook presents a discussion of the role of atomic and molecular orbitals in chemistry.This textbook presents a unified and up-to-date discussion of the role of atomic and molecular orbitals in chemistry. The text is mathematically less demanding than most traditional quantum chemistry books but still retains clarity and rigour. The relationships between the more formal quantum mechanical formalisms and the traditional chemical descriptions of chemical bonding are critically established. The book includes over 100 exercises with solutions. It will be valuable to upper-level undergraduate chemistry students and others taking courses of which chemistry is a significant part.This textbook presents a unified and up-to-date discussion of the role of atomic and molecular orbitals in chemistry. The text is mathematically less demanding than most traditional quantum chemistry books but still retains clarity and rigour. The relationships between the more formal quantum mechanical formalisms and the traditional chemical descriptions of chemical bonding are critically established. The book includes over 100 exercises with solutions. It will be valuable to upper-level undergraduate chemistry students and others taking courses of which chemistry is a significant part.This text presents a unified and up-to-date discussion of the role of atomic and molecular orbitals in chemistry, from the quantum mechanical foundations to recent developments and applications. Abundantly illustrated, the volume critically establishes the relationships between the more formal quantum mechanical formalisms and the traditional chemical descriptions of chemical bonding. It is mathematically less demanding than most traditional quantum chemistry texts, yet still retains clarity and rigor. This volume is an ideal textbook for any course in which chemistry is a significant part.1. Energy, probability and electrons; 2. An introduction to the dynamics of microsystems; 3. One electron ls,