For the NEQ approach, end state simulations were performed in the interacting state (state A) and the decoupled state (state B) using the same general procedure (minimization and equilibration) as in the EQ approach. Then, either the first nanosecond (in the case of toluene) or the first 5 ns of the production run was discarded for equilibration and frames extracted every 40 ps (T4 lysozyme) or every 50 ps (HSP90). Fast switching transitions from state A to B (A2B) and vice versa (B2A) were performed where the ∆λ = 1/n steps where n steps is the number of steps. Since electrostatics and sterics were switched simultaneously, a softcore potential was applied for both non-bonded interactions with the soft-core parameter sc-alpha=0.5, sc-power=1 and sc-sigma=0.3, as is typical.