“…By the separation of the electrons in a given system, complex many-electron problem can be simplified as the single electron problem and so can be solved easily. This theory has been developed by Zheng [20,21] and has been applied to calculate various atomic properties such as energy levels, ionization potentials, transition probabilities, oscillator strengths and lifetimes of excited levels in the many-electron atomic and ionic systems [22][23][24][25][26]. In the WBEPM theory, electronic radial wave functions are presented as a function of the Laguerre polynomial in terms of some parameters which are determined using the experimental energy data and the expectation values of radii [22][23][24][25][26],…”