System size and trajectory length dependence of the static structure factor and the diffusion coefficient as calculated from molecular dynamics simulations: The case of SPC/E water

► Very long molecular dynamics simulations of SPC/E water. ► Self diffusion constant and static structure factor are calculated as a function of system size and simulation length. ► MSD-based calculation of the self diffusion constant is more stable. ► Structural quantities are the least biased ones for comparing simulation and experiment.