SPATIAL STRUCTURE FORMULAE FOR TETRAHEDRAL LAYERS IN SILICATE STRUCTURES
硅酸盐结构中四面体层立体结构式的表述法

In this paper a method was created to represent the tetrahedral layers insiliacte structures using the spatial structure formulae. The basic symbolformat of a tetrahedral layer is made up by the orientation symbol U, D, V and H of tetrahedrals which constitute fundamental structure units or structure units. In case of the structure of silicate is visualized as repeating of atetrahedra layer, its spatial structure formula can be written by adding thedirection and distance of translation or translation-transformation gliderotatory-translation in inversion-translation for the structural unit to the sitedefined. On the criber hand, where the structure of silicate is treated asrepeating of two tetrahedral layers, its spatial structure formula can bewritten by adding the connection modes and thickness of the tetrahedral layerexcept the direction and distance for the structural unit. Some silicates withframework structures can be considered as superimposing or repeating of thetetrahedral layer in a spatial form and so their structures can be representedby the spatial structural formulae.