  A full set of calculations is presented for inner-shell n = 2 to 3
photoexcitation of the 16 iron charge states: Fe I through Fe XVI. The blend of
the numerous absorption lines arising from these excitations (mainly 2p - 3d)
forms an unresolved transition array (UTA), which has been recently identified
as a prominent feature between 16 - 17 \AA in the soft X-ray spectra of active
galactic nuclei (AGN). Despite the blending within charge-states, the ample
separation between the individual-ion features enables precise diagnostics of
the ionization range in the absorbing medium. Column density and turbulent
velocity diagnostics are also possible, albeit to a lesser accuracy. An
abbreviated set of atomic parameters useful for modeling the Fe 2p - 3d UTA is
given. It is shown that the effects of accompanying photoexcitation to higher
levels ($n \ge$ 4), as well as the associated photoionization edges, may also
be relevant to AGN spectra.
