QUANTITATIVE RELATIONS AMONG CRYSTAL STRUCTURES ZEOLITES OF NATROLITE - EDINGTINITE GROUP. Malinovsky Y. Institute of Crystallography of Russian Academy of Sciences, Leninskii pr.59., Moscow, 117333, Russia; Burzlaff H., Rothammel W. Institut fur - Angevandte Physic der Universitat Erlangen- Nurnberg, Bismarckstr. 10, D-91054, Erlangen, Germany.

The comparative quantitative evaluation of crystal structure similarity degree was applied to small group of zeolite minerals. A procedure of quantitative evaluation is based on the concept of mapping [1]. A derived structure (2) is called to be related to a basic one (1) if it can be mapped by a pair of matrices(A,S). A is a non-singular 3x3 matrix, S is a (3x1) column matrix. M=(A,S) is called the mapping of the relationship. The special computer program was created [2]. The type of symmetry relationship among more than 10 structures of natrolite-edingtonite-scolecite-thomsonit-kalborsite series was shown. There is a strong specific influence of cation type on the tetrahedral network. The influence of different cations (in row H-Na-K-Rb-Ca-Ba) on - other atomic positions in the structure is quantitavely estimated. The role of water molecules was discussed.

[1] Burzlaff H., Rothammel W., On Quantitative - Relations among Crystal Structures, Acta Cryst. A 48 (1992), pp.483-490.

[2] Malinovsky Yu.A., Burzlaff H.,Rothammel W., Structure of Lovozerite Type - a Quantitative Investigation, Acta Cryst. B 49 (1992), pp.158-164