Oscillator strengths and collision strengths for S IV

Collision strengths for S IV for excitation between the fine structure levels of the 3s(2) 3p for ground state and excited states 3s3p(24)P, 2D, 2P, and 2S are calculated in two-state and five-state close-coupling approximations for the energy range 1.3-6.0 R. Configuration-interaction target wave functions which gave oscillator strengths accurate to 10% are used in the expansion. Comparison with beam-foil experimental data is good. It is concluded that use of elaborate wave functions is more important than the choice of the scattering approximation.