A photoelectric absorption with variable abundances using
Balucinska-Church and McCammon (ApJ
400, 699) cross-sections. The column for each
element is in units of the column in a solar abundance column of an
equivalent hydrogen column density of 10 
cm 
. The Solar abundance
table used is set by the abund command.
par1-par18 = equivalent columns for H, He, C, N, O, Ne, Na, Mg, Al,Si, S, Cl, Ar, Ca, Cr, Fe, Ni, Co
par19 = redshift