Quantum Dynamics of Water from Møller-Plesset Perturbation Theory via a Neural Network Potential

We report the static and dynamical properties of liquid water at second-order Møller-Plesset perturbation theory level (MP2) with classical and quantum dynamics simulations using a neural network potential. We examined the temperature-dependent radial distribution function, diffusion and vibrational dynamics. MP2 theory predicts an over-structured liquid water at ambient conditions, which may be attributed to the incomplete basis set. The excellent agreement with experimental structural properties as well as the diffusion constant is observed at an elevated temperature of 340K.