Complex Coordinates in the Theory of Atomic and Molecular Structure and Dynamics

Each of these processes is typified by the formation and decay of an intermediate state, or resonance, which is a nonstationary (or quasibound) state with a lifetime long enough to be well characterized, and long enough to make its explicit recognition of experimental and theoretical importance. The simplest, and most naive, mathematical description of such states is that they resemble bound stationary states in that they are localized in space (at t =0), and their time evolution