I have got a divergence problem which I do not have a clue about.
I need to simulate a reflectance spectrum of a pressed pellet of milled calcite, so I generated a bulk material consisting of little rectangles. To simulate a random orientation of the dielectric tensor function I assign a rotation attribute to every rectangle, and every rotation attribute gets another set of Euler angles. If every rotation attribute gets the same set of angles, everthing is fine, the autoshutoff decreases to the given value. If every rotation attribute gets a different set of Euler angles, the autoshutoff decreases to almost the given value and then suddenly increases, until the simulation stops due to divergence. Why is that? Where is the problem?
Attached are the FDTD fsp file, the Calcit_Pressling.lsf file to generate the bulk material and the create_calcite.lsf file to generate the anisotropic material.
Thanks for any kind of help,