Electron collision excitation of fine-structure levels in SIV

Electron collision excitation strengths of inelastic transitions among the 52 fine-structure levels of the ground 3s(2)3p and excited 3s3p(2), 3s(2)3d , 3s(2)4s, 3p(3),3s(2)4p, 3s3p3d, 3s(2)4d, 3s(2)4f; and 3s3p4s configuratio ns in S IV are calculated using full Breit-Pauli R-matrix method. The targe t levels are represented by configuration-interaction wave functions, and t he mass, Darwin, and spin-orbit relativistic terms are included in the scat tering equations. The collision strengths in the threshold energy regions a re dominated by the complicated resonance structures. Our collision strengt hs are compared with earlier available calculations and significant differe nces are noted. The collision strengths are integrated over a Maxwellian di stribution of electron energies to obtain effective collision strengths ove r a wide temperature range.