The papers collected in this volume have been presented during a workshop on "Electron-Atom and Molecule Collisions" held at the Centre for Interdisciplinary Studies of the University of Bielefeld in May 1980. This workshop, part of a larger program concerned with the "Properties and Reactions of Isolated Molecules and Atoms," focused on the theory and computational techniques for the quanti tative description of electron scattering phenomena. With the advances which have been made in the accurate quantum mechanical characterisation of bound states of atoms and molecules, the more complicated description of the unbound systems and resonances important in electron collision processes has matured too. As expli cated in detail in the articles of this volume, the theory for the quantitative explanation of elastic and inelastic electron molecule collisions, of photo- and multiple photon ionization and even for electron impact ionization is well developed in a form which lends itself to a complete quantitative ab initio interpretation and pre diction of the observable effects. Many of the experiences gained and the techniques which have evolved over the years in the com putational characterization of bound states have become an essential basis for this development. To be sure, much needs to be done before we have a complete and detailed theoretical understanding of the known collisional processes and of the phenomena and effects, which may still be un covered with the continuing refinement of the experimental tech niques.

Inhalt
Electron-Photon Angular Correlation and Spin Effects in Electron-Atom Collisions.- Variational Methods in Electron-Molecule Collisions.- The Schwinger Variational Principle: An Approach to Electron-Molecule Collisions.- Recent Developments in Complex Scaling.- Algebraic Variational Method Close-Coupling Models for Electron Excitation of One Electron Targets.- Scattering Calculations with L2 Basis Functions: Gauss Quadrature of the Spectral Density.- Molecular Resonance Phenomena.- The R-Matrix Theory of Electron-Molecule Scattering.- Recent Developments of the Frame Transformation Theory of Electron Molecule Processes.- Recent Developments of the Frame Transformation Theory of Electron Molecule Processes.- On the Influence of Exchange on Electronic Continuum Function in Diatomic Molecules.- Decay of Feshbach Resonances in Diatomic Molecules.- Computational Models for e?-Polyatomics Low-Energy Scattering.- Dynamical Theory of Resonant Electron-Molecule Scattering Near Threshold.- Electron Impact Ionization of Positive Ions.- Aspects of Electronic Configuration Interaction in Molecular Photoionization.- The Time-Evolution of Photo-Ionization by Multiple Absorption of Photons.- The Laser as a Tool to Supress the Background of Resonances and Threshold Effects in Electron Scattering.