COMPUTATIONAL MODELING OF AMORPHOUS SILICA .2. MODELING THE INITIAL STRUCTURES - AEROSIL

A qualitative algorithm for constructing large clusters of aerosil model structures is used According to this algorithm and the classification of amorphous silicas, aerosil is classified with tectosilicas, which are characterized by close packing of silicon-oxygen tetrahedra. Two quantitative algorithms for constructing large close-packed clusters are proposed. The structures of the clusters having from 10 to 24 silicon atoms, completely optimized by quantum chemical methods, were obtained. Small, medium, and large clusters for modeling the local and collective properties of atomic and functional group packing in the aerosil structure are distinguished