Simulation techniques constrained sampling methods

The relationship in Eq. [28] can be used for a single solute pair if simulations are performed using the umbrella sampling technique.In this method, the solute-solute distance is constrained to lie within a small window, allowing for the efficient calculation of g r) over that restricted distance range. The effect of the constraint is subtracted from the calculated u> r) after the fact. Results from several overlapping windows may be combined to yield the full potential of mean force. 

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