Approximation of Hartree-Fock atomic form factors within the shell model

On the basis of the shell model for the electron distribution in an atom, analytic expressions and approximations are constructed for relativistic Hartree-Fock atomic form factors. The proposed approach ensures a precision that is two to three times higher than that of approximations based on existing models. This approach makes it possible to obtain simple expressions for a screening function of the Thomas-Fermi type.