Excitation of heliumlike ions by electron impact

Five-state close-coupling equations for electron-heliumlike-ion scattering are solved in the energy region from near threshold to five times threshold energy. Collision strengths for excitation of the ground state to the $n=2$ states (2³S, 2¹S, 2³P⁰, and 2¹P⁰) are presented for Liii, Cv, Ovii, and Sixiii. Fair quantitative agreement is obtained with the measurements of Rogers et al. for Ω(1¹S, 2³P⁰) for Liii. Rate coefficients are given in parametrized form.