All MD simulations are performed using the i-PI code interfaced with LAMMPS , which implements the NNP potential using N2P2 . We used 128 water molecules at experimental density (0.997 g/mL) to perform long-timescale molecular dynamics simulations. To achieve efficient canonical sampling while minimally perturbing the dynamics, the temperature of classical MD simulations was controlled using a stochastic velocity rescaling (SVR) thermostat , with a time constant of 1000 fs. A timestep of 0.5 fs was used.