Accurate numerical solution of the radial Schrödinger and Dirac wave equations Original Research Article

A FORTRAN 77 subroutine package for the numerical solution of the Schrödinger and Dirac wave equations for central fields is presented. The considered fields are such that the function ν(r) ≡ rV(r) is finite for all r and tends to constant values for r → 0 and r → ∞. This includes finite-range fields as well as combinations of Coulomb and short-range fields. The potential energy function V(r) used in the calculation is the natural cubic spline that interpolates a table of values provided by the user. The radial wave equations are solved by using piecewise exact power series expansions of the radial functions, which are summed up to the prescribed accuracy so that truncation errors can be completely avoided. Normalized radial wave functions, eigenvalues for bound states and phase shifts for free states are evaluated.