A model to fit the soft excess in AGN by partially ionized absorbing material with large velocity shear. It approximates this by using XSTAR kn5 photoionization absorption model grids (calculated assuming a microturbulent velocity of 100km/s), and then convolving this with Gaussian smearing. This is the model used by Gierlinski & Done 2006, Sobolewska & Done 2006 and Done et al 2006. It is an update (uses a newer version of XSTAR) of the original model of Gierlinski & Done 2004.
par1 = column density (1022 cm-2)
par2 = log(xi) where xi=L/nr2
par3 = sigma : Gaussian sigma for velocity smearing (v/c)
par4 = redshift