Materials Data on HfSiS by Materials Project
HfSiS is Matlockite structured and crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Hf is bonded in a 9-coordinate geometry to four equivalent Si and five equivalent S atoms. All Hf–Si bond lengths are 2.79 Å. There are four shorter (2.65 Å) and one longer (2.84 Å) Hf–S bond lengths. Si is bonded to four equivalent Hf and four equivalent Si atoms to form a mixture of distorted corner, edge, and face-sharing SiHf4Si4 hexagonal bipyramids. All Si–Si bond lengths are 2.50 Å. S is bonded in a 5-coordinate geometry to five equivalent Hf atoms.