Volume 51, Number 11, 1783-1794, DOI: 10.1134/S0036023606110155

Cluster self-organization of Na,Ti-silicate systems: Suprapolyhedral precursors and self-assembly of crystal structures of Na2Ti2Si2O9 (Ramzaite) and Na2TiSiO5 (paranatisite)

G. D. Ilyushin

View Related Documents

Abstract

The initial stages of formation of precursor clusters are considered in an evolving system containing various types of polyhedra: T tetrahedra and M polyhedra (pyramids, octahedra, and others). A graph topological representation of the precursor clusters of different self-organization levels of a chemical system is given. The model has been applied to find precursor clusters for Na,Ti-silicates that crystallize in the Na-Ti-Si-O(H) systems. For ramzaite Na2Ti2Si2O9 (RAM) and a dimorph of natisite (NAT), namely, paranatisite Na2TiSiO5 (PNAT), computer techniques (the TOPOS 4.0 program package) have been used to perform the full 3D reconstruction of structure self-assembly: precursor cluster-primary chain-microlayer-microframework (supraprecursor). New types of eight-polyhedral ring precursor clusters have been identified. The packing specifics of precursor clusters in crystal-forming microlayers determine the platy habit of Na,Ti-silicate single crystals.
Original Russian Text © G.D. Ilyushin, 2006, published in Zhurnal Neorganicheskoi Khimii, 2006, Vol. 51, No. 11, pp. 1894–1905.

Fulltext Preview

Image of the first page of the fulltext document