A New Method for Calculation of Eigenstates for a System of a Core and Two Valence Nucleons

A method for calculation of eigenvalues and eigenstates for a system of a core and two valence nucleons is suggested. It consists of approximating the potential by a sum of separable terms, for which the Lippman-Schwinger equation is solved exactly. The wave functions have the exact "three-particle" asymptotic form, and approximate the "two-particle" asymptotics.