Interrelation between variational principles for scattering amplitudes and generalized <i>R</i>-matrix theory

C. William McCurdy; Thomas N. Rescigno; Barry I. Schneider

doi:10.1103/PhysRevA.36.2061

Interrelation between variational principles for scattering amplitudes and generalized R-matrix theory

C. William McCurdy, Thomas N. Rescigno, and Barry I. Schneider

Phys. Rev. A 36, 2061 – Published 1 September 1987

Abstract

We establish a connection between the Kohn variational principle, with (complex) outgoing-wave boundary conditions, and the Kapur-Peierls form of the R-matrix theory. We show that the complex Kohn method, unlike the usual Kohn method, does not suffer from the problem of spurious singularities. We also discuss a generalization that allows the calculation of scattering cross sections over a continuous range of energies from a single diagonalization of the Hamiltonian. Several numerical examples are presented.