The equilibrium density predicted by the Minnesota functionals is estimated by scanning over volume changes around trajectory snapshots . For each snapshot, total energies are calculated at scaled values of the lattice constant. The intramolecular coordinates are held fixed while the positions of the centers of mass of the water molecules are rescaled to scan over volume reductions and expansions. The equilibrium volume and density are determined by calculating the minimum of the interpolated energy values, at a given snapshot. 30 snapshots were used, each separated by 0.2 ps, to obtain a representative set of configurations. The density is calculated from the average equilibrium volume over all snapshots. Given that the basis set size varies with the volume of the box in plane wave basis sets, a larger wavefunction cutoff energy of 200 Ry was used to ensure reliable energy differences from these calculations.