METADYNAMICS WITH A NEW ADAPTED BIAS POTENTIAL

There have been challenges in the calculation of the free energy of complex systems. These problems are associated with sampling phase space, due to high free energy barriers of these systems. Here we focus our attention on formation of a biased potential for sampling potential energy surfaces. In fact we construct a biased potential by sampling the accessible region of phase space during the course of molecular dynamics simulation. This biased potential is then added to the system and the next biased potential is added to the pre-existing biased potential till the whole surface is filled and the barrier is overcome. This method has been validated against two test models; free energy associated to separating a pair of Lennard-Jones (LJ) particles and free energy for surmounting torsional barrier in butane. In all cases it is shown that the methods work efficiently and the convergence rate is even faster than the known methods in the literature, like metadynamics.