Didysprosium hepta-nickel

Abstract

The title compound, Dy 2Ni 7, adopts the β-Gd 2Co 7-type structure type. The asymmetric unit contains two Dy sites (both site symmetry 3m) and five Ni sites (site symmetries.m,.2/m and 3̄m, and two 3m). The four different Ni coordination polyhedra are Frank-Kasper icosa-hedra formed by five Dy and seven Ni atoms, four Dy and eight Ni, three Dy and nine Ni, and six Dy and six Ni atoms, respectively. The two different Dy coordination polyhedra are either pseudo Frank-Kasper icosa-hedra formed by two Dy and 18 Ni atoms or normal Frank-Kasper icosahedra formed by four Dy and 12 Ni atoms.