This paper discusses the properties of scattering–dominated active galactic nuclei ( AGN ) .
We define these to be AGN for which the direct line-of-sight to the continuum source is obscured by Compton-thick material .
The aim is to construct , for the first time , a model consistent with X-ray line luminosities , line ratios and various luminosity indicators .
The ASCA spectra of six such sources show several X-ray lines that can be reliably measured , mostly due to highly ionized magnesium , silicon sulphur and iron .
These enable us to investigate the physical conditions of the scattering material .
The sources show evidence of He-like and H-like iron lines that are likely to be produced in hot ( T \sim 10 ^ { 6 } K ) photoionized gas .
By measuring the EW of the lines , and by constructing a diagnostic line-ratio diagram , we demonstrate that the silicon and magnesium lines are produced by the same gas emitting the highly ionized iron lines .
The properties of this gas are rather different from the properties of warm absorbers in type I AGN .
Neutral 6.4 keV iron lines are also detected , originating in a different component which can be either Compton-thin or Compton-thick .
The best measured iron lines suggest an enhancement of { n _ { Fe } / n _ { H } } by a factor \sim 2 compared to solar , in both the hot and cool Compton-thin components .
We further show that in four of the sources , the Fe K \alpha ( 6.4 keV ) /H \beta ( \lambda 4861 \AA ) line ratio is consistent with that predicted for typical narrow line region clouds , and the reddening corrected H \beta is known , provided the column density is larger than \sim 10 ^ { 22.5 } cm ^ { -2 } , \alpha _ { ox } is smaller than 1.3 .
For some sources , this is a viable alternative to the commonly assumed Compton thick medium as the origin of the 6.4 keV iron line .

Subject headings : galaxies : abundances - galaxies : Seyfert - galaxies : active - line : formation - X-ray : galaxies