Photophysics of Highly-Excited States.- 1. Introduction.- 2. Quantum Defect Theory.- 3. Core Effects.- 4. Intermolecular Rydberg Correlations.- 5. Field Effects.- 6. Rydberg States in Condensed Media.- 7. Concluding Remarks.- Methods for Studying Higher Excited States in Molecules and Molecular Crystals by Means of Synchrotron Radiation.- 1. Introduction.- 2. Properties of Synchrotron Radiation Sources: A Short Overview.- 3. Some General Aspects of Synchrotron Radiation Instrumentation.- 4. Absorption and Reflection Spectroscopy.- 5. Time-Resolved and Energy-Resolved VUV Luminescence Spectroscopy.- 6. Photoemission.- 7. Perspectives.- 8. Appendix.- Nonlinear Optics and Laser Spectroscopy in the Vacuum Ultraviolet.- 1. Introduction.- 2. Vacuum Ultraviolet Lasers.- 3. Nonlinear Optical Methods for Producing Tunable VUV Radiation.- 4. Applications to Chemical Physics.- 5. Future Goals.- Multiphoton Ionization and Third-Harmonic Generation in Atoms and Molecules.- 1. Introduction.- 2. Resonantly-Enhanced Multiphoton Ionization.- 3. Multiphoton Ionization and Third-Harmonic Generation in Rare Gases.- Electron-Impact Spectroscopy of Molecules.- 1. Introduction.- 2. General Theory.- 3. Experimental.- 4. Experimental Results.- Elements of Quantum Defect Theory. I. Introduction and Formalism.- 1. Introduction to Quantum Defect Theory.- 2. Multichannel Quantum Defect Theory in Atoms.- Elements of Quantum Defect Theory. II. A Unified Theory of Rydberg and Autoionizing States.- 1. Introduction.- 2. Eigenchannel Quantum Defect Theory.- 3. Ab initio Calculations of Quantum Defect Parameters.- 4. Applications.- Elements of Quantum Defect Theory. III. Diatomic Molecules.- 1. Introduction to Molecular QDT.- 2. Comparison with Experiment.- 3. Inclusion of Molecular Dissociation.- Negative-Ion States.- 1. Introduction.- 2. Negative-Ion Properties.- 3. Unimolecular Electron Attachment.- 4. Multiply-Charged Negative Ions.- 5. Photoabsorption by Negative Ions.- 6. Recent Studies of Long-Lived He Negative Ions.- 7. Production of Negative Ions by Photon Reactions.- 8. Collision of High-Rydberg Atoms with Electron-Attaching Molecules and the Possible Influence of Dipole Bound States.- 9. Negative Ions of Molecular Clusters.- Superexcited nd Ionic State Relaxation Processes in Vacuum Ultraviolet Excited Polyatomic Molecules.- 1. Introduction.- 2. Fundamental Processes.- 3. Competing Decay Channels of Superexcited States.- 4. Methods for Studying Superexcited and Ionic States and Their Relaxation Processes.- 5. Further Remarks on Molecular Autoionization.- 6. Decay of Ion States.- Photoionization Dynamics of Small Molecules.- 1. Introduction.- 2. Shape Resonances in Molecular Photoionization.- 3. Molecular Autoionization.- 4. Concluding Remarks.- Photodissociation Dynamics of Gas-Phase Small Molecules.- 1. Introduction.- 2. ICN Photodissociation in the Near Ultraviolet.- 3. VUV Photodissociation of HCN.- 4. VUV Photodissociation of the Cyanogen Halides.- 5. Conclusions.- VUV Spectroscopy of Rare-Gas Van Der Waals Dimers.- 1. Introduction.- 2. General Background.- 3. Experimental Apparatus.- 4. Dependence of the Cluster Ion Signals on Nozzle Stagnation Pressure.- 5. Appearance Potentials of the Dimer Ions and Dissociation Energies of the Dimer-Ion Ground States.- 6. Molecular Rydberg Structure Between the Atomic Fine-Structure Thresholds: Dissociation Energies of X+2(C 2?1/2u) and XY+(B 2?1/2 and D 2?1/2+).- 7. Molecular Rydberg Structure in the Spectra of NeY Near the Ne 3s Atomic Resonance.- 8. Molecular Rydberg Structure in the Spectra of ArKr and ArXe Near the Ar 5s and 3d Atomic Resonances.- 9. Molecular Rydberg Structure in the Spectra of X2 and XY Near the High-Lying Atomic Rydberg States.- 10. Summary and Conclusions.- Excitons and Energy Transfer in Insulators.- 1. Prologue.- 2. Frenkel Excitons.- 3. Wannier Excitons.- 4. Deep Wannier Atomic Impurity States.- 5. Excitons and Impurity States in Rare-Gas Fluids.- 6. Molecular Wannier Impurity States in Rare-Gas Solids.- 7. Excited-State Dynamics in Rare-Gas Solids.- 8. Self-Trapping of Excitons in Rare-Gas Solids.- 9. Lattice Relaxation Around Impurity States.- 10. Electronic Relaxation of Impurity States.- 11. Electronic Energy Transfer in Rare-Gas Solids.- 12. Perspectives.- Regular and Irregular Motion in Classical and Quantum Systems.- 1. Introduction: Order and Chaos.- 2. Integrable Systems.- 3. Perturbation of Integrable Systems and the KAM-Theorem.- 4. Area-Preserving Mappings.- 5. Chaotic Systems.- 6. A Generic System is Neither Integrable Nor Ergodic, But Shows a Stochastic Transition.- 7. The Birkhoff-Gustavson Normal Form and Invariant Tori Below the Critical Energy.- 8. Do Quantum Systems Exhibit Chaotic Behavior?.- 9. Integrable Systems and Tori Quantization.- 10. Quantization of Chaotic Systems.- 11. Statistics of Energy Levels.- 12. Quantizing a Generic System.- 13. Conclusions and Discussion.- New Trends in Atomic Diamagnetism.- 1. Introduction.- 2. The Coulomb Spectrum.- 3. The Landau Spectrum.- 4. The Atom in a Magnetic Field.- 5. Classical Mechanics of Diamagnetism.- 6. Quantum Mechanical Approach.- 7. Semi-Classical Methods.- 8. Experimental Studies in Atomic Physics.- 9. Prospects and Conclusions.- Evidence for Motional Electric Field Effects in the Absorption Spectrum of Lithium Vapor in a Magnetic Field.- 1. Introduction.- 2. Results and Discussion.- On the Spectrum Of V(?) $$V\left( \rho \right) = - \frac{{qt}}{\rho } + \frac{{rt}}{{{\rho ^2}}} + stp + t{p^2}.$$. Physical Implications for a Variety of Problems.- 1. Introduction.- 2. Solution of the Eigenvalue Problem.- 3. Applications.- 4. Summary.- Perturbation Spectroscopy.- 1. Introduction.- 2. Perturbation Theory and MCD Spectroscopy.- 3. Electric Field-Effect Spectroscopy.- 4. Pressure-Effect Spectroscopy.- Circular Dichroism and Magnetic Circular Dichroism Studies in the Vacuum Ultraviolet.- 1. Introduction.- 2. Instrumentation.- 3. Results.- Electric Field Studies in the Vacuum Ultraviolet.- 1. Introduction.- 2. Experimental.- 3. General Results.- 4. Excited-State Parameters.- 5. Arc-Suppressor “Solvent” Effects.- 6. Conclusions.- Valence-Shell and Rydberg Transitions in Large Molecules.- 1. Introduction.- 2. The Rydberg Concept.- 3. From Spectra to Photochemistry.- 4. Rydberg States of Transition Metal Complexes.- Multiphoton Spectroscopy and Photochemistry.- 1. Introduction.- 2. Nonlinear Photochemistry.- 3. Two Examples.- 4. Other Systems.- Excess Energy Dependence of Vibrational Relaxation and Photophysical Branching Ratios in Isolated Aromatic Molecules: Relevance to Vacuum Ultraviolet Photochemistry.- 1. Introduction.- 2. Spectral Characteristics of Gas-Phase Fluorescence.- 3. Excess-Energy Dependence of Radiationless Transitions: Theory.- 4. Excess-Energy Dependence of Radiationless Transitions: Experiment.- 5. Intramolecular Vibrational Relaxation.- 6. Photochemical Implications of the Energy Dependence of Electronic Relaxation Processes.- Theoretical Studies of the Electronic Structure and Spectra of NH3+.- 1. Introduction.- 2. Franck-Condon Analysis of the 2A1(NH3+) ? 1A1 (NH3) Spectrum.- 3. Ab initio Calculations on Low-Lying States of NH3+.- Theoretical Correlations of Organic Photochemical Reactions in the VUV.- 1. Introduction.- 2. 1,4-Cyclohexadiene.- 3. Methylene Cyclopropane.- Photochemistry of Saturated Alcohols and Open-Chain Ethers at 185 nm in the Liquid Phase.- 1. Introduction.- 2. Discussion.- Photolysis of Cyclic Ethers and Acetals at 185 nm in the Liquid Phase.- 1. Discussion.- List of Participants.