Molecular mode-coupling theory for supercooled liquids: Application to water

We present mode-coupling equations for the description of the slow dynamics observed in supercooled molecular liquids close to the glass transition. T he mode-coupling theory (MCT) originally formulated to study the slow relax ation in simple atomic liquids, and then extended to the analysis of liquid s composed by linear molecules, is here generalized to systems of arbitrari ly shaped, rigid molecules. We compare the predictions of the theory for th e q-vector dependence of the molecular nonergodicity parameters, calculated by solving numerically the molecular MCT equations in two different approx imation schemes, with "exact" results calculated from a molecular dynamics simulation of supercooled water. The agreement between theory and simulatio n data supports the view that MCT succeeds in describing the dynamics of su percooled molecular liquids, even for network forming ones. [S1063-651X(99) 06210-8].