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.
