2012A&A...547A..87L

We have carried-out parallel intermediate-coupling frame transformation R-matrix calculations for electron-impact excitation amongst the 204 close-coupling levels of the 2s^x2p^y (x+y=3), 2s²{3,4}l, 2s2p{3,4}l, and 2p²3l configurations for all boron-like ions from C⁺ to Kr³¹⁺. We have also included the configuration interaction due to the 2p²4l, 2s3l3l' and 2p3s3l configurations. A detailed comparison has been made of the target structure and excitation data for four specific ions (viz., Ne⁵⁺, Ar¹³⁺, Fe²¹⁺ and Kr³¹⁺) that span the sequence, so as to assess the accuracy over the entire sequence. Effective collision strengths (Υs) are presented at temperatures ranging from 2x10²(z+1)² K to 2x10⁶ (z+1)² K (where z is the residual charge of the ions, i.e. Z-5). Detailed comparisons for the (effective) collision strengths (Υs) Ω are made with the results of previous calculations for the four representative ions. Furthermore, we examine the iso-electronic trends of the effective collision strengths as a function of temperature.