Aluminosilicates limitations with calculations

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... 

---