Recombination of O^2+^ ions by electron capture from atomic hydrogen in photo-ionized nebulae.

Detailed calculations are presented of cross sections and rate coefficients at thermal energies for electron capture by ^3^P ground state O^2+^ ions from atomic hydrogen. The rate coefficient remains practically constant, between 1.1 and 1.2x10^-9^cm^3^/s in the temperature range from 200 to 20000K. The rate coefficient for electron capture by O^2+^ to ions in the metastable ^1^D or ^1^S states is negligible at temperatures less than 10^6^K.