Complex Stabilization Method for Resonant Phenomena

A technique is presented which can be used to compute the complex poles of the resolvent (defined as resonances) directly by use of a square-integrable basis without a coordinate rotation and without explicitly imposing a boundary condition such as a Siegert resonant boundary condition. Such a technique is directly applicab$\stackrel{\mathrm{`}}{\mathrm{l}}$e to all phenomena which can be put in the form of a resonance such as photoionization, field ionization, and electron resonances in atoms and molecules.