SYNTHESIS, CRYSTAL-STRUCTURE, ELECTRONIC-STRUCTURE, AND PROPERTIES OFHF2IN5, A METALLIC HAFNIDE WITH ONE-DIMENSIONAL HF-HF AND 2-DIMENSIONAL IN-IN BONDING

Hf2In5-previously reported with the tentative composition ''Hf3In4''-w as prepared from the elements in a tantalum tube at 970 K. The X-ray d iffractional characterization by means of single-crystal refinement re veals the presence of a tetragonal structure (a = 1024.71(9), c = 305. 66(3) pm, P4/mbm, Z = 2) of Mn2Hg5 type. Hf2In5 is Pauli-paramagnetic and good metallic conductor. Quasi-relativistic semiempirical and scal ar-relativistic ab initio band structure calculations reveal Hf2In5, t o be a hafnide, composed of a two-dimensional indium network threaded by infinite hafnium chains. The amount of In-In bonding scales counter intuitively with the interatomic distances.