Resonances in the two-center Coulomb problem and unstable periodic orbits

Abstract
Broad resonance states associated with unstable periodic orbits in the two-center Coulomb problem are studied using a quantization scheme in which the real part of each resonance energy is determined by a Bohr-Sommerfeld-type loop integral over a periodic orbit and the imaginary part of the resonance energy is related to the Lyapunov index of the periodic orbit.