PERSYS—A program for the solution near the origin of coupled channel Schrödinger equation with singular potential Original Research Article

The code PERSYS produces the regular solution of a system of coupled Schrödinger equations near the origin, where the potential exhibits a singularity, due to the centrifugal, spin-orbit and Coulomb components. The solution is calculated by means of a highly accurate method, which consists of a perturbative technique in which the centrifugal term is taken as the reference potential while the rest of terms are seen as a perturbation.