The formula of Bates and Flannery for the low-density limit to three-body ionic recombination is used to determine the rates of N${\mathrm{O}}^{+}$ and N${\mathrm{O}}_2^{-}$ recombining in various gases and of ${\mathrm{O}}_4^{+}$ and ${\mathrm{O}}_2^{-}$ recombining in oxygen. Satisfactory agreement with the experimental values of Mahan and Person and of McGowan is obtained.

• Received 12 November 1968

DOI:https://doi.org/10.1103/PhysRevLett.21.1729