Atomic data for opacity calculations. III. Oscillator strengths for C II

Abstract
For pt.II. see ibid., vol.20, p.6379-97 (1987). The close-coupling methods described in paper II are used to calculate oscillator strengths, f, for all transitions between energy levels of C II having effective quantum numbers V<or=10 and total orbital angular momenta L<or=3 (a total of 1851 f values). The wavefunctions used for the 'target' states are the same as those employed in previous R-matrix calculations for collisional excitation of C III (Berrington et al 1987) and for energy levels of C II (Berrington and Seaton 1985). The average difference between f values calculated using the length and velocity operators is 3.7%. Calculated lifetimes for 11 C II levels are in good agreement with those from accurate measurements by Reistad et al 1986 (average difference of 7%).