Preface Ix molecular motion is considered through rotation-vibration coupling. The discus- sion of the hydrogen atom, the sole content of Chapter 10, is standard, but, as for the isotropic oscillator, accidental degeneracy is stressed. Chapter 1l is included to demonstrate to the student that there are angular momenta in quantum mechanics other than orbital and spin angular momenta. It includes the introduction of the Lenz vector, its consequences and ramifications. This subject is not usually covered at the introductory level, but it is certainly not beyond the beginning student The material in the remaining four chapters depends heavily upon approxima tion methods. Chapter 12 presents time-independent approximation methods, while Chapter 13 illustrates the use of these methods to solve problems of physical in- terest. One problem that is included in Chapter 13, albeit superficially, is the effect of fine structure on the shell model of the nucleus. Chapter 14 treats the Stark and Zeeman effects. Particular attention is paid to the consequences of breaking the spherical symmetry of central potentials by application of an external field. Chapter 15 presents time-dependent approximation methods, followed by a discussion of tomic radiation including the einstein coefficients There are more than two hundred problems. a detailed solutions manual is avail- ble. There are a number of appendixes to the book, including the answers to all problems for which one is required. Among the other appendixes is one listing the Greek alphabet with notations on common usage of these symbols in the book There is also a short table of acronyms used in the book. The remaining appendixes contain material that is intended to be quick reference material and helpful with the core material in the book. a list of( the inevitable) corrections can be found at http://users.stlcc.edu/cburkhardt/andhttp://www.umsl.edu/-ijl/homepage/ We are indebted to several people, without whose help this manuscript would not have been completed. Helen and Charles Burkhardt, parents, read the manuscript critically. Discussions with Dr J. D. Kelley were invaluable, as was his critical read- ing of the manuscript. Professor. S. T. Manson also read the manuscript and made many useful suggestions. Discussions with Dr. M. J. Kernan were very helpful, as were her suggestions. To all of these people we offer our sincere thanks. Charles e. BurkhardtPreface ix molecular motion is considered through rotation–vibration coupling. The discus￾sion of the hydrogen atom, the sole content of Chapter 10, is standard, but, as for the isotropic oscillator, accidental degeneracy is stressed. Chapter 11 is included to demonstrate to the student that there are angular momenta in quantum mechanics other than orbital and spin angular momenta. It includes the introduction of the Lenz vector, its consequences and ramifications. This subject is not usually covered at the introductory level, but it is certainly not beyond the beginning student. The material in the remaining four chapters depends heavily upon approxima￾tion methods. Chapter 12 presents time-independent approximation methods, while Chapter 13 illustrates the use of these methods to solve problems of physical in￾terest. One problem that is included in Chapter 13, albeit superficially, is the effect of fine structure on the shell model of the nucleus. Chapter 14 treats the Stark and Zeeman effects. Particular attention is paid to the consequences of breaking the spherical symmetry of central potentials by application of an external field. Chapter 15 presents time-dependent approximation methods, followed by a discussion of atomic radiation including the Einstein coefficients. There are more than two hundred problems. A detailed solutions manual is avail￾able. There are a number of appendixes to the book, including the answers to all problems for which one is required. Among the other appendixes is one listing the Greek alphabet with notations on common usage of these symbols in the book. There is also a short table of acronyms used in the book. The remaining appendixes contain material that is intended to be quick reference material and helpful with the core material in the book. A list of (the inevitable) corrections can be found at: http://users.stlcc.edu/cburkhardt/ and http://www.umsl.edu/∼jjl/homepage/. We are indebted to several people, without whose help this manuscript would not have been completed. Helen and Charles Burkhardt, parents, read the manuscript critically. Discussions with Dr. J. D. Kelley were invaluable, as was his critical read￾ing of the manuscript. Professor. S. T. Manson also read the manuscript and made many useful suggestions. Discussions with Dr. M. J. Kernan were very helpful, as were her suggestions. To all of these people we offer our sincere thanks. Charles E. Burkhardt Jacob J. Leventhal