Figure ). For small steps in the parameter values, this approach significantly reduces the possibility of discontinuities manifesting in the T M F as the same minimum is far more likely to be identified in successive T M F evaluations. An exception to this arises in the case where two minima coalesce on the intermolecular energy hypersurface. When this occurs, the stationary point corresponding to the shallower minimum (higher U inter value) transitions through a saddle point for some intermediate parameter values, and eventually the two wells combine to produce a single well. This is unfortunately an unavoidable consequence of the formulation of Problem (PE).