One-Dimensional Projection of Collective Variables for Effective Sampling of Complex Chemical Reaction Coordinates.

A one-dimensional projection (ODP) technique is introduced to overcome the challenges in multidimensional sampling. With the help of a projected "advancement of reaction (ξ)" control parameter, it was demonstrated that multidimensional samplings could be performed with a single parameter, thus dramatically reducing the computational overhead. In our test studies, the ODP technique successfully yielded the free energy surface of the double proton transfer reaction of the acetic acid dimer and the hydrolysis of the methyl diazonium ion. In short, the ODP can be a promising protocol for the samplings of complex chemical reaction dynamics.