چكيده فارسي :
In the present work studies the theoretically the potential energy expectation value 〈V〉 for beryllium atom and like ions for different excited states (1S² 2S^1 nS^1), 1S² 2S^1 nP^1) () (where Z = 4. 13) and calculate the difference between each state to the same level , was used in this study wave function Hartree – Fook and the results contained in this search match with the published results of Hartree – Fook in 2003 (source 25) . been taking values of (n = 4, 5) to the (1S² 2S^1 nS^1) state and (n = 2, 3) of the 1S² 2S^1 nP^1) state . The computer system Mathcad (Ver 2001i) is used in the present calculations after designing the required program.
