Front Cover; Advances in Atomic and Molecular Physics, Volume 18; Copyright Page; Contents; Contributors; Chapter 1. Theory of Electron-Atom Scattering in a Radiation Field; I. Introduction; II. Bremsstrahlung; III. Asymptotic States; IV. Scattering Theory; V. Generalized Low-Frequency Approximations; VI. Concluding Remarks; References; Chapter 2. Positron-Gas Scattering Experiments; I. Introduction; II. Experimental Techniques for Total Cross-Section Measurements; III. Total Cross-Section Results; IV. Differential Scattering Cross Sections; V. Inelastic Scattering Investigations. VI. Resonance SearchesVII. Possible Future Directions for Positron Scattering Experiments; References; Chapter 3. Nonresonant Multiphoton Ionization of Atoms; I. Introduction; II. The Theory of Multiphoton Ionization; III. Absolute Measurements of Multiphoton Ionization Cross Sections; IV. Experimental Results: Comparison with Theory; V. Destructive Interference Effects; VI. New Trends; VII. Conclusion; References; Chapter 4. Classical and Semiclassical Methods in Inelastic Heavy-Particle Collisions; I. Introduction; II. Angle-Action Variables; III. Rotational Excitation. IV. Uniform ApproximationsV. Semiclassical Theories; VI. Conclusions; References; Chapter 5. Recent Computational Developments in the Use of Complex Scaling in Resonance Phenomena; I. Introduction; II. Gamow-Siegert States; III. Complex-Coordinate Theorems and Properties of the Wave Functions; IV. Variational Principle; V. Variational Calculations; VI. Many-Body Theories; VII. Nondilation Analytic Potentials; VIII. Complex Stabilization Method; IX. Discussion; References; Chapter 6. Direct Excitation in Atomic Collisions: Studies of Quasi-One-Electron Systems; I. Introduction. II. Theoretical ModelsIII. Experimental Techniques; IV. Results and Discussion; V. Conclusions; References; Chapter 7. Model Potentials in Atomic Structure; I. Introduction; II. Simple Semiempirical Model Potentials; III. Potentials Based on Hartree-Fock Formalism; IV. Core Polarization; V. Relativistic Model Potentials; VI. Conclusions; References; Chapter 8. Recent Developments in the Theory of Electron Scattering by Highly Polar Molecules; I. Introduction; II. General Formulation; III. Approaches and Approximations; IV. Applications; V. Conclusion; Nomenclature; References. Chapter 9. Quantum Electrodynamic Effects in Few-Electron Atomic SystemsI. Introduction; II. One-Electron Systems; III. Light Muonic Systems; IV. Two-Electron Systems; V. Few-Electron Systems; VI. Concluding Remarks and Suggestions for Future Work; References; Index; Contents of Previous Volumes.