| We have recently introduced an efficient sampling and free energy calculation technique within the adaptive biasing potential (ABP) framework.[1] By mollifying the density of states we obtain an approximate free energy and an adaptive bias potential that is computed directly from the population along the coordinates of the free energy. This approximation introduces two parameters: strength of mollification and the initial Gaussian height. This method is simple to apply to free energy or mean force computation as it does not involve second derivatives of the reaction coordinates. We present here two extensions to deal with complex systems. The first extension consists in using a local and adaptive Gaussian height. In particular, adapting the height with the bias evolution rate prevents getting trapped in narrow but deep wells. The second extension introduces new approximations in order to efficiently sample free energy surfaces with more than 3 dimensions. |
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