Materials Data on K3TbSi3(HO5)2 by Materials Project
K3TbSi3(HO5)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 1-coordinate geometry to two equivalent H1+ and nine O2- atoms. Both K–H bond lengths are 2.96 Å. There are a spread of K–O bond distances ranging from 2.66–3.28 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to one H1+ and eight O2- atoms. The K–H bond length is 3.04 Å. There are a spread of K–O bond distances ranging from 2.76–3.36 Å. Tb3+ is bonded to six O2- atoms to form TbO6 octahedra that share corners with six SiO4 tetrahedra. There are a spread of Tb–O bond distances ranging from 2.24–2.36 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent TbO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 40–46°. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent TbO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 6–54°. There is two shorter (1.61 Å) and two longer (1.68 Å) Si–O bond length. H1+ is bonded in a distorted single-bond geometry to two K1+ and two O2- atoms. There is one shorter (1.01 Å) and one longer (1.67 Å) H–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, one Tb3+, one Si4+, and one H1+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three K1+, one Tb3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to four K1+, one Tb3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to three equivalent K1+, one Si4+, and one H1+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Tb3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+ and two Si4+ atoms.