Aluminosilicates quantum mechanical calculations

Two methods for including explicit electrostatic interactions are proposed. In the first, and more difficult approach, one would need to conduct extensive quantum mechanical calculations of the potential energy variation between a model surface and one adjacent water molecule using thousands of different geometrical orientations. This approach has been used in a limited fashion to study the interaction potential between water and surface Si-OH groups on aluminosilicates, silicates and zeolites (37-39). 

Aluminosilicates are important as both inorganic compounds and as minerals and mineral glasses. Quantum mechanical calculations on cluster models for aluminosilicates can now accurately reproduce their energetic, structural and spectral properties. Species in glasses can be identified by matching their calculated spectral properties with experiment. More important, such calculations provide a framework for relating the structures and properties of inorganic aluminosilicates and their mineral coimterparts. 

J.A. Tossell, Quantum mechanical calculation of Na NMR shieldings in silicates and aluminosilicates. Phys. Chem. Miner. 27, 70-80 (1999)... 

In the present chapter, the stability and properties of the nanostructured aluminosilicates wiU be reviewed and discussed with the focus on the computer modeling of such systems. The first theoretical investigations on the aluminosilicate NTs were mostly based on force fields specially developed for these systems (Tamura Kawamura, 2002). The size of the unit cell is normally a limitation for using quantum mechanical calculations. Notwithstanding, quantum mechanical methods are being apvplied to such systems. Density functional theory (DPT), presently the most popular method to perform quantum-mechanical calculations, is the state-of-the-art method to study day mineral nanotubes with high predictive power. First applications used the apvproximation to DFT implemented to the SIESTA (Artacho et ah, 1999 Soler et ah, 2002) code, which uses pseudo potentials and localized numerical atomic-orbital basis sets and it is well parallelized for multicore machines. Recently, the helical symmetry has been implemented in the CRYSTAL (Dovesi et... 

The use of quantum mechanics in the analysis of the structure and energetics of complex soil phases is a nontrivial task and often involves several ambiguous interpretations of the results. There are, however, a handful of studies that have successfully applied quantum methods to the analysis of layered aluminosilicate phases. Among the more useful of these quantum studies involving periodic calculations are those of Hess and Saunders (1992) and I lobbs et al. (1997) of kaoli-... 

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