Recombination coefficients for the 5g-4f transitions of OIII at nebular temperatures and densities

We calculate effective recombination coefficients for the formation of the 5g - 4f lines of O III in the intermediate coupling scheme. Photoionization data for the 5g levels calculated using the R-matrix method are used to de rive their recombination coefficients. Cascading from higher states is incl uded, allowing for the effects of finite electron density in a hydrogenic a pproximation. We explicitly include the distribution of population between the two ground levels of O (3+) in the calculation of the line intensities. The results are presented as a simple programmeable formula allowing the c alculation of recombination line intensities for electron temperatures, T-e in the range 5000 - 20 000 K and electron densities, N-e in the range 10(2 ) - 10(6) cm(-3).