Energy conservation issue
This problem was reported on Yahoo against c17.01, but it also occurs on the trunk. The attached sim aborts quite quickly due to energy non-conservation issues. On the trunk the code aborts after zone 457 in the first iteration. Adding the COSMIC RAYS BACKGROUND command has very little influence on the model, but has the side-effect of disabling the conservation check. This allows the line stack to be printed, yielding the following excerpt (this was stopped after zone 470 in the first iteration):
Inci 0 40.357 439.0272
....
H 1 2431.34A 40.409 494.8441
H 1 1215.67A 39.497 60.6556
Inwd 1215.67A 39.497 60.6556
Coll 1215.67A 37.946 1.7023
Pump 1215.67A 40.318 401.6615
Heat 1215.67A 38.484 5.8856
So the two-photon continuum is stronger than the entire incident continuum. Also the Lya pumping is very high, and that seems to be related (including NO INDUCED PROCESSES makes the crash go away).