R-matrix electron-impact excitation data for the B-like iso-electronic sequence

We have carried-out parallel intermediate-coupling frame transformation R-matrix calculations for electron-impact excitation amongst the 204 close-coupling levels of the 2sx2py (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 2 × 102(z + 1)2 K to 2 × 106(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.