RAPINI-PAPOULAR CONSTANTS IN A MODEL NEMATIC LIQUID-CRYSTAL

The force constants for homeotropic surface anchoring of a model Gay-B erne nematic liquid crystal are derived by a local density functional method with data from molecular dynamics simulations. For the molecule -surface interaction both an anisotropic and an isotropic one-particle potential is taken. It is found that the values of the anchoring stre ngths are barely affected by the anisotropy of the surface potential, which indicates predominance of packing effects. Additionally, a surfa ce-induced smectic A phase is being observed even though the phase is unstable in the bulk.