There should be no intersection. Are you sure OpenMEEG does not check for a minimal distance between these surfaces? I did not use OpenMEEG. I used MNE-Python on these models. It also crashes when surfaces are intersecting. All the models run through my code which checks for intersecting surfaces and "push" the outer surface out of the inner one and then they have been check with MNE-Python and they were working fine, not intersecting. I did not set a minimum distance (like >1 mm) between surfaces so if Open MEEG apply such criteria, it might complain... one model in particular is causing problem for you?