Computation of the eigenvalues of the schrodinger equation by exponentially-fitted Runge-Kutta-nystrom methods

In this work we consider exponentially fitted Runge Kutta Nystrom methods. These methods integrate exactly differential systems whose solutions can be expressed as linear combinations of the set of functions exp(wx), exp(-wx), or sin(wx),cos(wx), w epsilon R. We modify existing RKN methods order four to six and apply these methods to the computation of the eigenvalues of the Schrodinger Equation.