On the subdivision of structures isopointal to MoSi2and CaC2types

Abstract

AbstractStructure geometry of a wide variety of compounds isopointal to (139)I4/mmm–eais discussed focussing on changes due to variation of both the free structure parameterzand the lattice parameter ratioc/a. Looking at eight points in the parameter space more closely it is shown that coordination polyhedra as well as bond lengths vary considerably within thec/a–z∼ (1.2 … 4.7) – (0.1 … 0.4)-plane. Considering all interatomic spacings in the ranged= 0 … 1.25athe concept of isodiastematics is used to provide arguments for further subdivision of members of these isopointal structures into known isoconfigurational types CaC2, MoSi2, CuZr2and XeF2. Non-next nearest neighbor interactions seem to govern the choice of the free parameters.