Abstract: The corrected Gramm-Schmidt method is employed in 3-splined fitting of photoionization cross sections which was calculated in the authors previous work.In the case of LTE approximation,photon and free electron are assumed to be in Planck and Maxwell distribution respectively.The present derivation shows that,the rate coefficients of photoionization and radiative recombination can be described analytically in terms of 3-splined fitting parameters.This formulation is applied to He-like Rb and He-like Nb ions,and some of the results are figured out and analysed.By means of averaging over initial states and summing over final states,the degeneration of rate coefficients that concern the level level transitions is analysed explicitely.With the attained result, comparison and evaluation have been made to the formula given by reference[1].

Key words: photoionization rate coefficient, radiative recombination rate coefficient, 3 splined fitting