HF2SE3, A NEW STRUCTURE IN THE BINARY HF-SE SYSTEM

Hf2Se3 was synthesized and its structure determined using the Rietveld method with X-ray powder diffraction data (Ti5S8 type, space group: P 6(3)mc, a = 3.7165(1) Angstrom, c = 12.4304(2) Angstrom, Z = 2 for Hf1 .35Se2, Rp = 0.0600, wRp = 0.0811). The Se atoms form a closed packed array of the h.c. type, the Hf atoms occupy octahedral interstices in alternating fully and 35% occupied layers.