Clusters, quantum cluster equilibrium theory

Handbook 60. U.S. Department of Agriculture, Washington, DC Weinhold F (1998) Quantum cluster equilibrium theory of liquids Illustrative apphcation to water. J Chem Phys 109 373-384... 

Quantum Cluster Equilibrium Theory of Phase Thermodynamics... 

F. Weinhold. Quantum cluster equilibrium theory of liquids general theory and computer implementation. J. Chem. Phys. 109, 367-72 (1998). 

R. Ludwig, O. Reis, R. Winter, F. Weinhold, and T. C. Farrar. Quantum cluster equilibrium theory of liquids temperature dependence of hydrogen bonding in liquid A-methylacetamide studied by IR spectra. J. Phys. Chem. B 102, 9312-18 (1998). 

P. Borowski, J. Jaroniec, T. Janowski, and K. Wolinski. Quantum cluster equilibrium theory treatment of hydrogen-bonded liquids water, methanol and ethanol. Mol. Phys. 101, 1413-21 (2003). [This paper suggests the need for more accurate treatment of free cluster rotations that become hindered librations at normal liquid densities, thus reducing the populations of larger clusters.]... 

The starting point for quantum cluster equilibrium (QCE) theory is the envisioned aggregation of monomeric species (W) into supramolecular clusters (W i = 1, 2,..., c) that are considered to be in simultaneous thermodynamic equilibria [cf. (13.55)] ... 

In these remarks, one can see a pioneering suggestion of a cluster mixture theory of liquids with short-range (exchange-like) forces, along the lines of Mayer cluster theory (Sidebar 13.5) or quantum cluster equilibrium theory (Section 13.3.4). 

In order to get more detailed information about, e.g., bond strengths and equilibrium geometries in transition metal systems it is necessary to include electron correlation. This can be done either by traditional ab initio quantum chemistry models, e.g., Cl-methods and coupled cluster methods, or by density functional theory (DFT) based methods. Correlated ab initio methods are often computationally very demanding, especially in cases where multi-reference based treatments are needed. Also, the computational cost of these methods increases dramatically with the size of the system. This implies that they can only be applied to rather small systems. 

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. 

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