MOCASSIN 2.02 manual
This keyword is usually followed by a set of parameters which are to be fed into the density law routine, included in the grid_mod module. Any density law can be specified by editing the code in the setGrid subroutine. If the nebula is homogeneous, this keyword must be omitted and the Hdensity keyword included instead. Note that if neither of the two keywords is included, and an external density file is not specified with the densityFile keyword, the nebular density distribution is left undefined and the simulation halted with an error message being produced.
0. 0. etc..