Chapter VI. Mineral Chemistry

Structural aspects of oxide and oxysalt crystals

“…However, they have only seen extensive predictive use in the area of tetrahedral framework structures, particularly zeolites (Smith, 1988). Smith (1977) considered possible ways to link planar threeconnected 63 nets in the third dimension to form four-connected three-dimensional nets as predictive models for tetrahedral framework structures (Fig. 4).…”

“…Simple ways of adding a vertical linkage to each node of a 63 net to give a four-connected three-dimensional net. The letters S and C denote whether a linkage is the same or different from adjacent linkages; after Smith (1977).…”

High-Pressure Technic1

“…The use of this procedure is illustrated in the work on steam to 450°C. (13,24). In the latter case the fluid is liquid at ordinary temperatures, but the same principle applies where the fluid under measurement is a gas (10, 20).…”

Framework structures derived from a novel type of trigonal secondary building unit with on-axis T atoms: the tridymite group

“…The systematic enumeration of (4; 2)-connected 3D nets (this notation denotes framework structures extended in three-dimensional space with every framework T atom being tetrahedrally coordinated by oxygen atoms, while every oxygen atom itself is connected to two T atoms) has proven to be a valuable tool in the structural classification of zeolites and molecular sieves (Alberti, 1979;Kerr, 1963;Sato, 1979;Smith, 1977Smith, , 1978Smith, , 1979Smith & Bennett, 1981, 1984Barrer & Villiger, 1969;Bennett & Smith, 1985). At the same time it predicts the existence of as yet unknown phases of potential importance.…”

“…Barrer, 1984) such as the sigma (~) transformation (Shoemaker, Robson & Broussard, 1973), (v) coordination sequences and radial distribution functions (Meier & Moeck, 1973, (vi) coordination networks (Sato, 1983;Sato & Ogura, 1981), (vii) slipping schemes (Sato & Gottardi, 1982) and (viii) the enumeration of 2D nets extended to 3D nets by the use of supplementary linkages (e.g. Smith, 1977Smith, , 1979. Detailed structural information on zeolite frameworks can be found in the recently revised Atlas of Zeolite Structure Types (Meier & Olson, 1987) and in a comprehensive review (Smith, 1988).…”