High-density equation of state for a two-dimensional Lennard-Jones solid.

We present a new equation of state for a two-dimensional Lennard-Jones (2D LJ-EOS) solid at high densities, ρ2D * ≥0.9. The new 2D LJ-EOS is of analytic form, consisting of a zero-temperature contribution and vibrational contributions up to and including the second anharmonic term. A detailed analysis of all contributing terms is performed. Comparisons between the 2D LJ-EOS and Monte Carlo simulation results show that the 2D LJ-EOS is very accurate over a wide range of temperatures in the high-density region. A criterion to find the temperature range over which the 2D LJ-EOS is applicable at a certain density is derived. We also demonstrate an application of the equation of state to predict an effective tangential pressure for the adsorbed contact layer near the wall in a slit-pore system. Tangential pressures predicted by this "2D-route" are found to be in qualitative agreement with those found by the more traditional virial route of Irving and Kirkwood.