Dielectronic recombination coefficient for Ni-like gadolinium

Dielectronic recombination (DR) coefficients for the ground-state ion of Ni-like ${}_{64}{}^{}{}_{}{}^{}\mathrm{Gd}$ have been calculated in the isolated-resonance approximation for temperatures in the range of 0.05≤T≤3 keV. The Auger and radiative rates of each doubly excited state were evaluated explicitly by using the multiconfiguration Dirac-Fock model. The calculations were carried out in the intermediate coupling. The effect of the configuration interaction was also included for the low-lying doubly excited states. The intermediate autoionizing states included in the present work are the states from the 3$d^{\mathrm{-}1}$4lnl’ (n≤10), 3$p^{\mathrm{-}1}$4lnl’ (n≤5), and 3$s^{\mathrm{-}1}$4lnl’ (n≤5) configurations. The dielectronic recombination coefficients for Ni-like ${}_{64}{}^{}{}_{}{}^{}\mathrm{Gd}$ from the present calculations are 1.33×${10}^{\mathrm{-}10}$ and 1.08×${10}^{\mathrm{-}10}$ ${\mathrm{cm}}^3$/sec for T=500 and 800 eV, respectively. The semiempirical Burgess-Merts formula has been found to overestimate the dielectronic recombination coefficients for the Ni-like ${}_{64}{}^{}{}_{}{}^{}\mathrm{Gd}$ by a factor of 5 for T≥250 eV.