Next, we describe the determination of β in the direct MaxFlux method when using FB-ENM. A larger β is desirable to approach the zero-temperature limit. However, an excessively large β undesirably renders the contribution of the low-energy region in eq 16 or 18 infinitesimal. Thus, a moderately large β must be determined. When using a realistic potential energy, it is empirically known that β = 10 eV -1 is an appropriate choice. 9,14