# An R -matrix package for coupled-channel problems in nuclear physics

## Description

Abstract We present an R -matrix Fortran package to solve coupled-channel problems in nuclear physics. The basis functions are chosen as Lagrange functions, which permits simple calculations of the matrix elements. The main input is the coupling potentials at some nucleus–nucleus distances, specified by the program. The program provides the collision matrix and, optionally, the associated wave function. The present method deals with open and closed channels simultaneously, without numerical instabilit... Title of program: rmatrix Catalogue Id: AEYP_v1_0 Nature of problem Solving coupled-channel problems for positive energies; the package provides the collision matrix and the associated wave function for given energy, spin and parity. Versions of this program held in the CPC repository in Mendeley Data AEYP_v1_0; rmatrix; 10.1016/j.cpc.2015.10.015 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018)