Computer simulation of the self-assembly of paulingite crystal structure from suprapolyhedral nanocluster precursors K6, K16, and K20

A combinatorial and topological analysis of the paulingite crystal structure (a = 35.093 , V = 43 217 (3); sp. gr. Im has been performed by computational methods using the TOPOS program package. The application of the complete expansion of the 3D factor graph into nonintersecting substructures of a cluster type has revealed three types of nanocluster precursors in the tetrahedral T framework: K6, K16, and K20; they consist of 6T, 16T, and 20T tetrahedra, which are involved in the matrix self-assembly of the crystal structure. The translated cell contains 44 clusters (8 K6+ 24 K16 + 12 K20). None of the clusters have shared T tetrahedra. Three cluster precursors form a crystallochemically complex structure with extraframework Na+/Ca2+ and K+/Ba2+ cations which carry out two structural functions as templates (stabilizing nanocluster precursors) and as spacers (filling the voids between precursors). The self-assembly code of the 3D structure from complementary bound nanocluster precursors is completely reconstructed in the form primary chain -> microlayer -> microframework -> aEuro broken vertical bar framework.