The Symmetric and Topological Code of the Cluster Self-Assembly of the Icosahedral Structure of (Rb13)(Rb2O)3 (Fm-3c, cF184) Metal Oxide

Abstract

A search for crystal structures of A n O m metal oxides containing icosahedral i–A@A12 cluster precursors is performed (TOPOS program package, ICSD and CRYSTMET databases). Among 1802 metal oxides, the local region represented by i–Cs@Cs12 is determined in the Cs7O (P-6m2) metal oxide. In the case of the (Rb13)(Rb2O)3 (Fm-3c, cF184, V = 12409.8 A3) metal oxide, the i–Rb@Rb12 cluster precursor with the symmetry m-3 and cluster spacers in the form of Rb–O–Rb chains, which occupy the pores in the threedimensional framework, are identified. Cluster i–Rb@Rb12 occupies position 8b with the highest possible crystallographic symmetry m-3 for icosahedron. The topological type of the basic 3D network, which characterizes the packing of cluster precursors Rb13, corresponds to a simple cubic 3D network P c (Pm-3m, cP1) with CN = 6. The symmetric and topological codes of the self-assembly processes of the crystal structure from the nanocluster precursors S 3 0 is fully reconstructed in the following form: primary chain S 3 1 → microlayer S 3 2 → microframework S 3 3 . Cluster precursors in the primary chain are flipped through 90° and are characterized by the maximum possible number of Rb–Rb bonds corresponding to 8 and this mechanism of local binding is realized at all stages of the self-assembly of the 3D framework structure. During the assembly of the primary chain and microlayer, there is additional binding of the Rb@Rb12 icosahedra via the Rb atoms of three-atomic cluster spacers Rb–O–Rb. In the 3D framework structure, in the local environment of Rb@Rb12, there are 12 Rb–O–Rb cluster spacers.