Wavevector-dependent transport, mode coupling

H. Mode Coupling Theory Calculation of Wavevector-Dependent Transport Properties... 

The relaxation equations for the time correlation functions are derived formally by using the projection operator technique [12]. This relaxation equation has the same structure as a generalized Langevin equation. The mode coupling theory provides microscopic, albeit approximate, expressions for the wavevector- and frequency-dependent memory functions. One important aspect of the mode coupling theory is the intimate relation between the static microscopic structure of the liquid and the transport properties. In fact, even now, realistic calculations using MCT is often not possible because of the nonavailability of the static pair correlation functions for complex inter-molecular potential. 

Recently, an interesting study of the molecular dynamics calculation of the wavevector dependence of the viscosity and the thermal conductivity of a Lennard-Jones fluid was reported [202]. The transport properties were found to decrease rapidly as the value of the wavevector k was increased from zero, and they were nearly zero when kxs is larger than 5. However, we are not aware of any mode coupling theory calculation of this interesting behavior. In fact, most of the theoretical expressions exist, but the numerical calculation is formidable. 

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