  Most astrophysical plasmas entail a balance between ionization and
recombination. We present new results from the powerful R-matrix method which
yields in an ab initio manner: (I) self-consistent photoionization and
recombination cross sections using identical wavefunction expansions, (II)
unified e-ion recombination rates at all temperatures of interest,
incorporating non-resonant and resonant processes, radiative and dielectronic
recombination (RR and DR), and (III) level-specific recombination rates for
many excited atomic levels. RR and DR processes can not be measured or observed
independently. In contrast to the shortcomings of simple (but computationally
easy) approximations that unphysically treat RR and DR separately with
different methods, emphasizing marginal effects for selected ions over small
energy ranges, the R-matrix method naturally and compeletely accounts for e-ion
recombination for all atomic systems.
  Photoionization and recombination cross sections are compared with
state-of-the-art experiments on synchrotron radiation sources and ion storage
rings. Overall agreement between theory and experiments is within 10-20 %. For
photoionization the comparison includes not only the ground state but also the
metastable states, with highly resolved resonance structures. The recent
experiments therefore support the estimated accuracy of the vast amount of
photoionization data computed under the Opacity Project (OP), the Iron Project
(IP), and related works using the R-matrix method.
