Modifies a noun

• theory: We extend the semiclassical theory of scarring of quantum eigenfunctions by classical periodic orbits to include situations where these orbits undergo generic bifurcations.

• method: Semiclassical Methods for Atoms and Molecules ( University of Nottingham, Great Britain ).

• limit: The study of how quantum systems, whose classical counterparts are chaotic, behave in the semiclassical limit has been called quantum chaos.

• model: Structure in the angular distributions is analyzed using a semiclassical optical model.

• approximation: This is known as the semiclassical approximation because its validity lies somewhere between that of classical and quantum physics.

• quantization: The semiclassical quantization of the normal form has been investigated and in some cases a very good agreement with quantum results was found.