THEORY FOR THE REORIENTATIONAL DYNAMICS IN GLASS-FORMING LIQUIDS

The mode-coupling theory for ideal liquid-glass transitions is extende d so that the structural relaxation for the reorientational degrees of freedom of a linear molecule, which is immersed in a system of spheri cal particles, can be described. Closed equations of motion for the co rrelation functions formed with tensor density fluctuations are derive d, which deal with the molecule's translational and reorientational mo tion. From these equations the nonergodicity parameters of a hard dumb bell molecule are calculated, which quantify its arrest in a hard-sphe re glass. For top-down symmetric molecules it is shown that the odd-an gular-momentum variables can exhibit an ergodic-to-nonergodic transiti on, characterized by a continuous increase of the Edwards-Anderson par ameters near the critical points.