A new variant of multicanonical Monte Carlo algorithm with specifying the temperature range and its application to the hydration free energy change of fluorinated methane derivatives

The multicanonical Monte Carlo simulation is often carried out making use of a weight factor which is decided with specifying the energy range. Here we present a new variant of multicanonical Monte Carlo algorithm, ‘selected-multicanonical Monte Carlo’, in which the range of temperature is specified instead of the energy range and the configurations are selected which fit the desired temperature range. The new method has the advantage of adequately deciding the weight factor to create multicanonical ensemble. The new method is applied to free energy perturbation calculation to obtain the hydration free energy changes of methane derivatives.