Abstract: | A new convenient and efficient finite-difference (FD ) method is developed for solving the pair radial equations (PRE ) of many electron perturbation theory (MPT ). This method can be interpreted as the FD analog of the well-known Fourier method. The method is used to solve PRE arising in the second order of MPT based on the hydrogenic and Hartree–Fock (HF ) zero approximations. Being very simple programmed our method gives results comparable with the most accurate variational calculations. |