Effective collision strengths for C II

Thermally averaged collision strengths are presented as a function of electron temperature for application to astrophysical plasmas. An accurate description of the target wave functions has been obtained in the multiconfiguration Hartree-Fock approach with flexible non-orthogonal orbitals.

The 42 fine-structure levels of the 2s^2^2p, 2s2p^2^, 2s^2^3l (l=0-2), 2p^3^, 2s^2^4l (l=0-3), 2s2p3s and 2s^2^5l (l=0-2) configurations have been included in the scattering calculation. A second calculation with lowest 35 levels in the close-coupling expansion has also been carried out to check channel coupling effects on collision strengths. The continuum functions have been represented by the use of B-spline basis.