Cluster Self-Organization of Intermetallic Systems: 124-Atom Cluster 0@12@32@80 and 44-Atom Cluster 0@12@32 for the Self-Assembly of Li48Na80Ga332-oF920 Crystal Structure

Abstract

A combinatorial and topological analysis has been performed and self-assembly of the Li₄₈Na₈₀Ga₃₃₂-oF920 crystal structure has been simulated (sp. gr. Fmmm, a = 24.666 Å, b = 15.974 Å, c = 45.271 Å, V = 17 837 ų) using computer methods (the TOPOS program package). It is found that there are 11 827 versions of cluster representation of an atomic 3D net with the number of structural units from 4 to 14. Two framework-forming icosahedral clusters ico-K124 and ico-K44 are determined. The chemical composition of the shells of the three-layer 124-atom nanocluster ico-K124 is 0@12(Ga₁₂)@32(Li₂₀Ga₁₂)@80(Li₄Na₁₆Ga₆₀), its diameter is 17 Å, and the symmetry is mmm. The chemical composition of the shells of the two-layer 44-atom nanocluster ico-K44 is 0@12(Ga₁₂)@32(Li₂₀Ga₁₂), its diameter is 11 Å, and the symmetry is 2/m. The symmetry and topology code of self-assembly of the crystal structure has been reconstructed from iсо-K124 and ico-K44 nanocluster precursors in the following form: primary chain → layer → framework. Ga₇ clusters and dual chains of Ga atoms occupy 3D-framework voids.