Quantum statistical first-principles calculation of proton and deutron transfer reactions

Shiga, Motoyuki   ; Fujisaki, Hiroshi*

We propose a new simulation method for simple evaluation of free energy curves of quantum systems by combining ab initio path integral method with string method. In this method, the center of mass positions of nuclei represented in terms of path integral formulation (centroid) is set as configurational variables, and the free energy surface is defined on this configuration space. Then, the minimum free energy reaction path on this surface is searched by the string method. This is one of the ways to generalise the idea of intrinsic reaction coordinate to quantum systems, and it could be useful for analysing proton and deutron transfer reactions.