  Narrow Line Seyfert 1 (NLSy1) galaxies have recently received a lot of
attention due to their unusual optical--X-ray properties which are not yet well
understood. Photoionization models of the circum-nuclear emission/absorption
regions allow to investigate scenarios to explain the main characteristics of
NLSy1s, i.e., (i) extremely steep X-ray spectra within the ROSAT energy range,
(ii) narrow Balmer lines and (iii) weak forbidden lines except for some
relatively strong high-ionization iron lines. Here, we focus on (iii). In
particular, we study the influence of different EUV - soft-X-ray spectral
shapes (a giant soft excess, a steep X-ray powerlaw, presence of a warm
absorber) and NLR cloud properties on the predicted optical emission-line
ratios. The calculations were carried out with Ferland's code Cloudy.
