The theory of atom-molecule collisions is one of the basic fields in
chemi- cal physics. Its most challenging part - the dynamics of chemical
reactions - is as yet unresolved, but is developing very quickly. It is
here a great help to have an analysis of those parts of collision theory
which are already complete, a good example being the theory of atomic
collisions in process- es specific to chemical physics. It has long been
observed that many notions of this theory can also be applied
successfully to reactive and unreactive molecular collisions. More-
over, atomic collisions often represent a touchstone in testing
approaches proposed for the solution of more complicated problems.
Research on the theory of slow atomic collisions carried out at the
Moscow Institute of Chemical Physics has been based on just these ideas.
A general viewpoint concerning the setting up and representation of the
theory came out of these studies, and appeared to be useful in studying
complicated systems as well. It underlies the representation of the
theory of slow atomic colli- sions in this book.