OPTICAL POTENTIALS BY THE COMPLEX COORDINATE METHOD

Recently, Jolicard and Austin (Chem. Phys. Letters 21 (1985) 106) proposed the inclusion of an "arbitrary" imaginary potential, known as "optical" potential, to the physical Hamiltonian in order to get the resonance position and width. We show here that such optical potentials can be obtained from the complex coordinate method (CCM), within the framework of the finite basis set approximation. This observation enables us to find a formal basis on which the optical potential method stands, and to give some insight into the choice of potential parameters. The optical potentials derived from the CCM are complex potentials, for which the resonance positions and widths are obtained as stationary solutions in the variational potential parameter space. An illustrative numerical example is given.