Cluster Self-Organization of Intermetallic Systems: K3, K4, K5, K6, and K13 Clusters-Precursors for the Self-Assembly of U8Ni10Al36-mC54, U20Ni26-mC46, and U8Co8-cI16 Crystal Structures

Abstract

Using computer methods (the ToposPro software package), a combinatorial topological analysis and modeling of the self-assembly of U8Ni10Al36-mC54 (a = 15.5470 Å, b = 4.0610 Å, c = 16.4580 Å, β = 120.00°, V = 899.89 Å3, C m), U20Ni26-mC46 (a = 7.660 Å, b = 13.080 Å, c = 7.649 Å, β = 108.88°, V = 725.26 Å3, C2/m), and U8Co8-cI16 (a = 6.343 Å, V = 255.20 Å3, I 213) are carried out. For the U8Ni10Al36-mC54 crystal structure, 960 variants of the cluster representation of the 3D atomic grid with the number of structural units 5, 6, and 7 are established. Six crystallographically independent structural units in the form of a pyramid K5 = 0@Al(U2Al2), pyramid K6A = 0@U(NiAl4), and pyramid K6B = 0@U(NiAl4), as well as rings K3A = 0@NiAl2, K3B = 0@NiAl2, and K3C = 0@Al3, are determined. For the U20Ni26-mC46 crystal structure, the structural units K5 = Ni(Ni2U2) and icosahedra K13= Ni@Ni6U6 are defined. For the crystal structure U2Co2-cI16, the structural units—tetrahedra K4 = U2Co2—are defined. The symmetry and topological code of the processes of self-assembly of 3D structures from clusters-precursors are reconstructed in the following form: primary chain → layer → framework.