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.