linear recurrence relation
1.The tangent of phase of phase shift function δ l(r) is expressed as a power series in wave vector k, and then substituted into the linear F. Calogero equation to get the recurrence relation of the coefficients. The phase shift and scattering length of the spherical square potential well and Yukawa potential scattering for low energy collisions were calculated, which were also compared with the numerical solutions of the different equations.
