Front Cover; Solid State Physics, Volume 21; Copyright Page; Contents; Contributors to Volume 21; Preface; Contents of Previous Volumes; Supplementary Monographs; Articles to Appear Shortly; Chapter 1. Insulating and Metallic States in Transition Metal Oxides; I. Introduction; II. Theoretical Models to Explain Electrical Properties; III. Experimental Results on Transition Metal Oxides; IV. Conclusions; Chapter 2. The Excitonic State at the Semiconductor-Semimetal Transition; I. Introduction; II. Screened Hartree-Fock Approximation; III. Single Valence Maximium and Single Conduction Minimum.

IV. Band Structures with Several Equivalent Electron or Hole PoketsV. Region near Eo+, the Semiconducting Transition Point; VI. Dynamic Linear Response Theory; VII. The Electron Phonon Coupling; VIII. Summary of Results of the Screened Hartree Fock Approximation; IX. Beyond Hartree-Fock; Appendix A: Some Symmetry for the Screened Hartree-Fock Matrix Elements; Appendix B: Choice of Basis Functions; Appendix C: Evaluation of the Singlet Triplet Splitting Constant; Chapter 3. Polarons; I. Introduction; II. Large Polaron Eigenstates; III. Large Polaron Mobility; IV. Small Polaron Eigenstates.

V. Small Polaron MobilityChapter 4. Magnetic Properties of Rare Earth Metals; I. Introduction; II. Equilibrium Magnetic Behavior; III. Theory of Spin Waves for the Ferromagnet; IV. Spin Waves for Periodic Moment Arrangements; V. Experimental Manifestation of Spin Waves; VI. Conduding Remarks; Author Index; Subject Index; Cumulative Contributor Index Volumes 1-20; Cumulative Topical Index Volumes 1-20.