Front Cover; Advances in Atomic and Molecular Physics, Volume 7; Copyright Page; Contents; List of Contributors; Contents of Previous Volumes; Chapter 1. Physics of the Hydrogen Maser; I. Introduction; II. Hydrogen Maser Techniques; III. Dynamical Behavior of the Maser; IV. Hyperfine Spectroscopy; V. Interaction of Atomic Hydrogen with Radio Frequency Fields; References; Chapter 2. Molecular Wave Functions: Calculation and Use in Atomic and Molecular Processes; I. Introduction and General Principles; II. Computations of Wave Functions, Potential Surfaces, and Coupling Matrix Elements

III. Some Results and Expectations for the FutureIV. Atom-Atom Scattering; V. Radiative Processes; References; Chapter 3. Localized Molecular Orbitals; I. Introduction; II. Density Matrix Formalism; III. The Edmiston-Ruedenberg Localization Method; IV. The Method of Boys and Foster; V. Direct Localization Methods; VI. Internal and External Localization Criteria; VII. The Method of Magnasco and Perico; VIII. The Method of Peters; IX. Molecular Orbitals Determined from Localization Models; X. Localized Orbitals in Expansion Methods; XI. Concluding Remarks; References

Chapter 4. General Theory of Spin-Coupled Wave Functions for Atoms and MoleculesI. Introduction; II. Properties of the Exact Electronic Eigenfunction; III. Construction of the Spin Functions; IV. The Spin-Coupled Wave Functions; V. Calculation of Matrix Elements of the Hamiltonian; VI. The Orbital Equations; VII. Symmetry Properties of the Spin-Coupled Wave Functions; VIII. The Hund's Rule Coupling; IX. The General Recoupling Problem and Bonding in Molecules; X. Conclusions; Note Added in Proof; Appendix A. Proof of the Relations (59)-(62)

Appendix B. Matrix Elements of Spin-Dependent OperatorsAppendix C. Proof That the Orbital Equations Are Invariant under H; Appendix D. Proof That the Operators F(a) and F(B) Are Invariant under Unitary Transformations of the 4Ou and ?u Sets of Orbitals; References; Chapter 5. Diabatic States of Molecules-Quasistationary Electronic States; I. Introduction; II. Mathematical Preliminaries; III. Molecular Ground States-The One-State Problem-The Stationary Adiabatic Representation; IV. The Na + CI Two-State Problem-Covalent and Ionic States

V. Charge Exchange in Helium-Single Configuration Diabatic StatesVI. Dissociative Recombination and Attachment-The Quasistationary State Represen tat ion; VII. Slow Heavy-Particle Collision Theory-Extension of the Quasistationary Representation to Rydberg States; VIII. Summary and Conclusion; References; Chapter 6. Selection Rules within Atomic Shells; I. Introduction; II. Groups; III. Irreducible Representations; IV. Generalized Triangular Conditions; V. Generators; VI. Conflicting Symmetries; VII. Oriented Spins; VIII. Special Cases; IX. Conclusion; References