Cluster Self-Organization of Intermetallic Systems. New Cluster Presursor (InNa5)(AuAu5) and Primary Chain with the 5m Symmetry for the Self-Assembly of the Na32Au44In24–oP100 Crystal Structure

Abstract

The combinatorial-topological analysis and simulation of the self-assembly of the Na32Au44In24–oP100 (space group P bcm, a = 5.483 A, b = 24.519 A, c = 14.573 A, V = 1895 A3) crystal structure are conducted by the computer-based methods (TOPOS program package). A new type of the 12-atom K12 cluster formed from doubled pentagonal pyramids—AuAu5 and InNa5—is established. The maximal symmetry of the K12 cluster and the primary chain of translationally bound K12 clusters correspond to the noncrystallographic 5m symmetry. The symmetry and topological codes of the Na32Au44In24–oP100 3D structure’s self-assembly processes from the K12 nanocluster precursors are reconstructed in the following form: primary chain → microlayer → micro-framework. The primary chains of bound K12 clusters with the m symmetry are located in the direction [100], and the distance between cluster centers determines the vector’s value: a = 5.483 A. There are four nonparallel primary chains in the primary chain’s local environment. The chains from InAu atoms and NaAu2In2 clusters are located in the 2D layer between the primary chains. The distance between the equivalent chains in the direction [001] determined the vector’s value: c = 14.573 A. In the 3D framework in the direction [010], the distance between the equivalent 2D layers determined the vector’s value: b = 24.519 A.