  The general formulas to calculate the phase shifts of wave function of a
particle scattering on a target formed by a pair of non-identical zero-range
potentials are derived. It is shown that at asymptotically great distances from
the target the continuum wave function of particle is presented as an expansion
in a set of other than spherical, orthonormal functions. General formulas for
these functions are obtained. The special features of the S-matrix method for
the case of arbitrary non-spherical potentials are discussed.
