Computer simulation of water between metal walls

Monte Carlo simulation has been used to investigate the structural and thermodynamic properties of water between two metallic (copper) planes ca. 23.0 Å apart. The water was represented by the ST2 model, and the metal-water interaction potential included contributions from dispersion (Lennard-Jones) and electrostatic image forces. Runs were performed with and without long-range corrections using the reaction field method. A weak, but definite, tendency for the planes of the molecules, especially those near the walls, to lie parallel to the walls was observed. The singlet distribution profiles for oxygen and hydrogen atoms showed oscillations which extended to the middle of the box; similar oscillations, although incommensurate with those in the atom profiles, were found in the corresponding orientational functions. Increasing the strength of all the image forces by a factor of two led to a marked effect on all the singlet distribution characteristics.