Fig. 4.

(Upper) Trajectory of three representative water molecules as they migrate from one adsorption site to neighboring ones on MgO (Left; no slip), W = 0 surface (Center; slip), and D = 0.70 surface (Right; slip). The two red lines on the top panels identify the position of the contact water layer. Surface solid atoms are identified by green and gray circles (Mg and O, respectively). The black line describes the trajectory of one water molecule. On the MgO substrate the trajectory is 35 ps long. On the W = 0 surface the trajectory is 20 ps long. On the D = 0.70 substrate the trajectory is 30 ps long. (Lower) Planar density distributions are reported on the bottom panels for water molecules at contact with the three surfaces after the Couette flow is fully established.