Quantum-mechanical modeling of defective Mg-Hydroxide/layer-silicate structures

The present research project aims to model by means of ab initio quantum mechanical approaches the structure of defective Mg-Hydroxide/layer-silicate and its interactions in specific sites with water and biological molecules such as DNA and proteins. In particular it is proposed to use CRYSTAL2006 code (Hartree-Fock and Density Functional) to model periodic (3D, 2D, 1D) systems belonging to the family of chlorites and cluster calculations on simplified models by means of GAUSSIAN03 for energy profiles of surface reactions. Firstly we will calculate surface properties such as geometry, potential and electron density which are useful to understand the interaction of these silicate surfaces with water and biological environment. Our study will be directed to model defective silicate structure by introducing octahedral and tetrahedral defects to understand the local variation of the surface potential and of the electron density with the aim to localize specific surface sites for the interaction with water and by molecules such DNA and proteins.