Calculation of the rate coefficients for the electron impact excitation of the n=2 terms of O IV

The collision strengths for the excitation of the n=2 terms in O IV from the ground and metastable terms have been calculated for energies from the first excitation threshold to 5.6 Ryd in a close-coupling approximation. The resonance structure obtained in the reactance matrices has been fitted and the resulting analytic fits used to generate the collision strengths at a fine energy mesh. These collision strengths were then integrated to obtain rate coefficients for temperatures between 10 4 and 2*10 5 K.