I've looked into this regression failure. The nmo attribute changes over the course of the optimization, so the assertions that nmo == self.nmo fail.

I see two fixes:

1. Don't use the assert statement for optimizations.
2. Keep track of nmo at each step in the optimization, and only assert for the current step.

Fix 1 seems most straight-forward, but fix 2 gives better error checking.

Thoughts?