LILIX—A package for the solution of the coupled channel Schrödinger equation Original Research Article

The code LILIX is based on a CP method for solving systems of coupled Schrödinger equations. The method is of the sixth order, highly stable and with uniform accuracy with respect to the energy. The package contains three main subroutines to be accessed directly by the user. Subroutine LI generates the partition consistent with the desired accuracy while subroutine LIX helps propagating the solution and its derivative with respect to the momentum k in both directions (forwards and backwards) along the mesh points of the partition. Subroutine RENORM helps conserving the linear independence of various vectors in the solution matrix whenever this may be of concern.