[en] The elastic scattering cross-sections are calculated both in the framework of Lindhard wide-angle extrapolation method and on the basis of an exact solution of the classical equation of motion of a particle in a central-force potential. Using a direct method for the numerical solution of integro-differential equations governing the ion implantation spatial distribution parameters, the projected ranges, projected and lateral stragglings, and skewnesses are calculated in a wide interval of reduced energies. It is shown that for incident energies epsilon < 0.1 all these parameters are affected by the choice of both the interatomic potential and elastic scattering cross-section approximation. (author)