Dynamics in a supercooled molecular liquid: Theory and simulations - art. no. 061210

We report extensive simulations of liquid supercooled states for a simple t hree-site molecular model, introduced by Lewis and Wahnstrom [Phys. Rev. E 50, 3865 (1994)] to mimic the behavior of ortho-terphenyl, The large system size and the long simulation length allow us to calculate very precisely ( in a large q-vector range) self-correlation and collective correlation func tions, providing a clean and simple reference model for theoretical descrip tions of molecular liquids in supercooled states. The time and wave-vector dependence of the site-site correlation functions are compared (neglecting the molecular constraints) with detailed ideal mode-coupling theory predict ions. Except for the wave-vector region where the dynamics are controlled b y the center of mass (around 9 nm(-1)). the theoretical predictions compare very well with the simulation data.