  The atmospheres of novae at early times in their outbursts are very extended,
expanding shells with low densities. Models of these atmospheres show that NLTE
effects are very important and must be included in realistic calculations. We
have, therefore, been improving our atmospheric studies by increasing the
number of ions treated in NLTE. One of the most important ions is Fe II which
has a complex structure and numerous lines in the observable spectrum. In this
paper we investigate NLTE effects for Fe II for a wide variety of parameters.
We use a detailed Fe II model atom with 617 level and 13675 primary lines,
treated using a rate-operator formalism. We show that the radiative transfer
equation in nova atmospheres {\em must} be treated with sophisticated numerical
methods and that simple approximations, such as the Sobolev method, {\em
cannot} be used because of the large number of overlapping lines in the
co-moving frame.
  Our results show that the formation of the Fe II lines is strongly affected
by NLTE effects. For low effective temperatures, $\Teff < 20,000\,$K, the
optical Fe II lines are most influenced by NLTE effects, while for higher
$\Teff$ the UV lines of Fe II are very strongly affected by NLTE. The departure
coefficients are such that Fe II tends to be overionized in NLTE when compared
to LTE. Therefore, Fe II-NLTE must be included with sophisticated radiative
transfer in nova atmosphere models in order to reliably analyze observed nova
spectra.
