Materials Data on BaHf(SiO3)3 by Materials Project

Abstract

BaHf(SiO3)3 crystallizes in the hexagonal P-6c2 space group. The structure is three-dimensional. Ba2+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Ba–O bond lengths are 2.82 Å. Hf4+ is bonded to six equivalent O2- atoms to form HfO6 octahedra that share corners with six equivalent SiO4 tetrahedra. All Hf–O bond lengths are 2.08 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent HfO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. There is two shorter (1.63 Å) and two longer (1.66 Å) Si–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+, one Hf4+, and one Si4+ atom.