Title: ELECTRON IMPACT EXCITATION OF Fe XXI

Authors: K. M. Aggarwal and F. P. Keenan

Affiliation: Department of Pure and Applied Physics, Queen's University, Belfast BT7 1NN, UK

Summary: Collision strengths for transitions among the lowest 46 fine-structure levels belonging to
the (1s$^2$) 2s$^2$2p$^2$, 2s2p$^3$, 2p$^4$ and 2s$^2$2p3${\ell}$ configurations of C-like
Fe XXI\ have been calculated, at 3 representative energies of 100, 200 and 300 Ryd, using
the Dirac $R$-matrix code. Configuration interaction as well as relativistic effects have
been included while generating the wavefunctions from the GRASP code. Detailed calculations
for collision strengths and rate coefficients are in progress.