A recursive Kohn variational algorithm for the Greenʹs operator: application to the T-matrix Original Research Article

A recursive version of the Kohn variational principle for the Greenʹs operator is presented. An expression for the off-shell T-matrix is derived which is valid in the presence of a hard wall potential and which is conveniently evaluated using the recursive algorithm. The off-shell T-matrix elements for scattering systems with and without hard wall components to the potential are computed using this algorithm.