Atomic data from the IRON Project - XXXIV. Electron impact excitation of Fe XVI

As part of the IRON Project, electron impact excitation effective collision strengths are computed for the ion Fe XVI familiar in solar spectra. A Bre it-Pauli R-matrix calculation is performed with a 12-level (n less than or equal to 4) target representation. The calculation for this relatively simp le ion is approached as a test case where we can analyze in detail most of the effects that contribute to the accuracy of the collision strengths: the energy mesh, relativistic corrections, the asymptotic multipole potentials and contributions from high partial waves. By comparing with two recent in dependent calculations, an accuracy rating of 10% is assigned to the presen t effective collision strengths in the electron-temperature range of 10(5) less than or equal to T/K less than or equal to 10(7).