Dielectronic recombination rate forMo31+

A detailed calculation of the dielectronic recombination (DR) rate coefficient is presented for the system ${\mathrm{Mo}}^{31+}+e^{-}$, in which the initial states of the ion are $i_1=1\mathrm{}{s}^{2}2s^{2}2p^{6}3s$, $i_2=1\mathrm{}{s}^{2}2s^{2}2p^{6}3p$, and $i_3=1\mathrm{}{s}^{2}2s^{2}2p^{6}3d$. All possible intermediate autoionizing states and their cascade decays are included. The necessary Auger and radiative transition probabilities are computed using nonrelativistic Hartree-Fock wave functions. Various angular-momentum-averaging schemes are examined, and a simple and general procedure applicable to all open- and closed-shell targets is developed. In this, the orbital and spin angular momenta of the Auger-active electron pair is held fixed while all other angular momenta are averaged. As expected, the main contribution to the DR rate comes from the excitation of $2p$ electrons (a $\Delta n\ne 0$ process). The overall DR rates for $i=i_2$ and $i=i_3$ are ∼30% less than the rate for $i=i_1$. The overall DR rate for $i=i_1$ is slightly greater, at 3 keV, than the rate for the ion ${\mathrm{Mo}}^{32+}$.