  Unified recombination cross sections and rates are computed for (e + Fe
XVIII) --> Fe XVII including non-resonant and resonant (radiative and
di-electronic recombination, RR and DR) processes in an ab initio manner with
relativistic fine structure. The highly resolved theoretical cross sections
exhibit considerably more resonance structures than observed in the heavy-ion
storage ring measurements at Heidelberg, Germany. Nonetheless, the detailed
resonance complexes agree well with experiment, and the unfiied rates agree
with the sum of experimentally derived DR and theoretical RR rates to ~ 20%,
within experimental or theoretical uncertainties. Theoretical results may
provide estimates of field ionization of rydberg levels close to the DR peak,
and non-resonant background contirbutions, particularly close to the RR peak as
E --> 0. More generally, the unified results avoid the physical and practical
problems in astrophysical models inherent in the separation of electronic
recombination into RR and DR on the one hand, and further subdivision into
low-energy Delta n = 0 DR and high-energy Delta n > 0 DR in photoionized and
collisionally ionized X-ray plasmas.
