  We calculate the efficiency of iron K line emission and iron K absorption in
photoionized models using a new set of atomic data. These data are more
comprehensive than those previously applied to the modeling of iron K lines
from photoionized gases, and allow us to systematically examine the behavior of
the properties of line emission and absorption as a function of the ionization
parameter, density and column density of model constant density clouds. We show
that, for example, the net fluorescence yield for the highly charged ions is
sensitive to the level population distribution produced by photoionization, and
these yields are generally smaller than those predicted assuming the population
is according to statistical weight. We demonstrate that the effects of the many
strongly damped resonances below the K ionization thresholds conspire to smear
the edge, thereby potentially affecting the astrophysical interpretation of
absorption features in the 7-9 keV energy band. We show that the centroid of
the ensemble of K$\alpha$ lines, the K$\beta$ energy, and the ratio of the
K$\alpha_1$ to K$\alpha_2$ components are all diagnostics of the ionization
parameter of our model slabs
