He is the Max Born professor of
Natural Philosophy at the
Hebrew University of Jerusalem and a distinguished professor at the
University of California, Los Angeles. He is known for his contributions in the modern theory of chemically reactive collisions and
unimolecular reactions. He has played a major role in the application of the principles of quantum mechanics to the description of physical change in a reaction from a microscopic point of view, introducing many new concepts and terms which became standard to this area. His major works include the quantum theory of absolute rates, the first quantal treatment of molecular photodissociation, elucidation of the role of resonances in reactive molecular collisions, the theory of collision- induced dissociation, and the foundations of dynamical stereochemistry. He is a member of
Israel Academy of Sciences and Humanities, the
Max Planck Society,
Academia Europaea,
American Academy of Arts & Sciences,
American Philosophical Society,
Royal Danish Academy of Sciences and Letters, and
National Academy of Sciences of the United States. He has honorary doctorates from Liege University, 1991 and the Technical University of Munich 1996. His 2005 book, "Molecular Reaction Dynamics", Cambridge University Press, was selected by Choice as 'Outstanding Academic Title 2006'. == Awards and recognition==