A common assumption is that x-ray structures represent at least some stable conformations from those populating real ensembles. We hypothesized that the comparison of MD trajectories originating from different candidate models to the x-ray reference would allow us to establish the correct one. Our models represented three most commonly applied protonation states of the hBChE extended active site: Glu197 and Glu441 could both be without protons, or one of them harboring one proton. Additionally, we modeled hBChE as both free and covalently inhibited by an OP. The latter results in the diethyl-phosphorylated hBChE (DEP-hBChE).