Mean field theory of the orientational properties of (J=1) hydrogen molecules on the surface of Grafoil

A mean field theory is developed which is applicable to the orientational behavior of (J = 1) hydrogen molecules on the surface of Grafoil. The hydrogen molecules are assumed to form a triangular lattice in a weak, axially symmetric crystal field, V c . perpendicular to the substrate and to interact via the electric quadrupole–quadrupole interaction with nearest-neighbor coupling constant Γ. Free energy calculations for the various possible …