Incorporating Nuclear Quantum Effects in Molecular Dynamics

The accurate incorporation of nuclear quantum effects in large-scale molecular dynamics simulations remains a significant challenge. Here, we develop a new formulation of the equations of motion of molecular dynamics that incorporates nuclear quantum effects, enabling molecular dynamics simulations to be performed on an effective energy surface obtained from a constrained energy minimization with given quantum nuclear expectation positions. Using a series of model systems, we find that this new approach is significantly more accurate in describing vibrations than classical molecular dynamics and can accurately describe tunneling, which classical molecular dynamics is unable to do. With a lower computational cost, this approach is comparable to or more accurate than centroid molecular dynamics and ring-polymer molecular dynamics.