Statistical geometry liquid structure

The most direct source of structural information, the diffraction studies, provides strong evidence for predominantly tetrahedral ordering of a molecule and its nearest neighbors, both in amorphous solid and liquid H2O. Other, weaker but still direct, structural evidence comes from the ratio of separations of nearest neighbor and next nearest neighbor 00 pairs in liquid water, the ubiquity of tetrahedral ordering in the several crystalline ices, and the statistical geometry of simulated water. 

Thermodynamics of the Weeks-Chandler-Andersen System Inherent Structure of Two-Dimensional Liquids Statistical Geometry of the Weeks-Chandler-Andersen System... 

The shapes of these self-assemblies are as varied as the capacity of the molecules to weave through space will allow. The accessible interfacial geometries span a rich range of structures from spheres and planes to highly intercormected bicontinuous honeycombs. So how are the structures of these complex liquid crystalline and disordered assemblies best described and understood Typically, the problem is tackled by recourse to thermodynamic principles. A complete statistical mechanical treatment is out of the question. (The difficulty is a fundamental one. We do not yet know how to write down a partition faction that describes the full ensemble of possible aggregate shapes and their associated free energies.)... 

The An cyclononatetraenyl cation was studied by Anastassiou and Yakali via the treatment of deuterium-labeled 9-chlorocyclononatetraene with liquid SO2 (an ionizing solvent), and they found that the deuterium became statistically distributed, presumably via the cation. They wondered why this An system could be so easily formed and proposed a helical geometry. Subsequent calculations by Schley-er et al. found that the lowest energy conformation of the ion did have a structure of this type, which leads to a Mobius 7r-electron system in which there is one inversion of phase. Compounds of this type were predicted by Heilbronner to have aromatic character, and the NICS value for this ion is in accord with this expectation. Calculations for other conformations of this ion have been reported. ... 

Solvation behavior can be effectively predicted using electronic structure methods coupled with solvation methods, for example, the combination of continuum solvation methods such as COSMO with DFT as implemented in DMoF of Accelrys Materials Studio. An attractive alternative is statistical-mechanical 3D-RISM-KH molecular theory of solvation that predicts, from the first principles, the solvation structure and thermodynamics of solvated macromolecules with full molecular detail at the level of molecular simulation. In particular, this is illustrated here on the adsorption of bitumen fragments on zeolite nanoparticles. Furthermore, we have shown that the self-consistent field combinations of the KS-DFT and the OFE method with 3D-RISM-KH can predict electronic and solvation structure, and properties of various macromolecules in solution in a wide range of solvent composition and thermodynamic conditions. This includes the electronic structure, geometry optimization, reaction modeling with transition states, spectroscopic properties, adsorption strength and arrangement, supramolecular self-assembly,"and other effects for macromolecular systems in pure solvents, solvent mixtures, electrolyte solutions, " ionic liquids, and simple and complex solvents confined in nanoporous materials. Currently, the self-consistent field KS-DFT/3D-RISM-KH multiscale method is available only in the ADF software. 

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