Molecular liquid state nonlinearity

The last comer of our ideal triangle symbolizes the reduced model theory (RMl). The last few years have heard some debates on how to build up a modeling approach to molecular dynamics in the liquid state. These earlier attempts are based mainly on the generalized Langevin equation of Mori, which is linear in nature. In this book we shall illustrate a nonlinear version of this approach, the application of which implies wide use of both the AEP and CFP. 

NONLINEAR EFFECTS IN MOLECULAR DYNAMICS OF THE LIQUID STATE... 

The main aim of this paper is to discuss the role played by nonlinearity in molecular dynamics in the liquid state. Earlier theoretical investigations on this subject (reported by M. W. Evans in Chapter V) are complicated by the fact that they have to interpret computer simulations of three-dimensional systems. As nonlinearity by itself involves technical and conceptual difficulties, it would be especially advantageous to focus on many-particle models which are capable of exhibiting the characteristic dynamical proper-... 

VI. Nonlinear Effects in Molecular Dynamics of the Liquid State 225... 

Liquid crystal polymers are also used in electrooptic displays. Side-chain polymers are quite suitable for this purpose, but usually involve much larger elastic and viscous constants, which slow the response of the device (33). The chiral smectic C phase is perhaps best suited for a polymer field effect device. The abiHty to attach dichroic or fluorescent dyes as a proportion of the side groups opens the door to appHcations not easily achieved with low molecular weight Hquid crystals. Polymers with smectic phases have also been used to create laser writable devices (30). The laser can address areas a few micrometers wide, changing a clear state to a strong scattering state or vice versa. Future uses of Hquid crystal polymers may include data storage devices. Polymers with nonlinear optical properties may also become important for device appHcations. 

Ray Kapral came to Toronto from the United States in 1969. His research interests center on theories of rate processes both in systems close to equilibrium, where the goal is the development of a microscopic theory of condensed phase reaction rates,89 and in systems far from chemical equilibrium, where descriptions of the complex spatial and temporal reactive dynamics that these systems exhibit have been developed.90 He and his collaborators have carried out research on the dynamics of phase transitions and critical phenomena, the dynamics of colloidal suspensions, the kinetic theory of chemical reactions in liquids, nonequilibrium statistical mechanics of liquids and mode coupling theory, mechanisms for the onset of chaos in nonlinear dynamical systems, the stochastic theory of chemical rate processes, studies of pattern formation in chemically reacting systems, and the development of molecular dynamics simulation methods for activated chemical rate processes. His recent research activities center on the theory of quantum and classical rate processes in the condensed phase91 and in clusters, and studies of chemical waves and patterns in reacting systems at both the macroscopic and mesoscopic levels. 

Our discussion has so far been concerned with the microscopic response of a molecule to an external electric field, and thus with an expansion of the molecular energy in orders of the response with respect to the external field, giving rise to the molecular (hyper)polarizabilities. Although experimental data for nonlinear optical properties of molecules in the gas phase do exist [55], the majority of experimental measurements are done in the liquid or solid states, as these states also are the ones that are of greatest interest with respect to developing materials with specifically tailored (non)linear optical properties. 

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