  We performed non-equilibrium Molecular Dynamics simulations of water flow in
nano-channels with the aim of discriminating {\it static} from {\it dynamic}
contributions of the solid surface to the slip length of the molecular flow. We
show that the regularization of the slip length divergence at high shear rates,
formerly attributed to the wall dynamics, is controlled instead by its static
properties. Surprisingly, we find that atomic displacements at the Angstrom
scale are sufficient to remove the divergence of the slip length and realize
the no-slip condition. Since surface thermal fluctuations at room temperature
are enough to generate these displacements, we argue that the no-slip condition
for water can be achieved also for ideal surfaces, which do not present any
surface roughness.
