DOI: 10.17188/1694605
title: Materials Data on Ba3HfTa4O15 by Materials Project

description: Ba3HfTa4O15 crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 2-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.74–3.17 Å. In the second Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.85–2.96 Å. In the third Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share faces with two equivalent BaO12 cuboctahedra, faces with two equivalent HfO6 octahedra, and faces with six TaO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.75–2.92 Å. Hf4+ is bonded to six O2- atoms to form HfO6 octahedra that share corners with two equivalent HfO6 octahedra, corners with four TaO6 octahedra, and faces with two equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 4–46°. There are a spread of Hf–O bond distances ranging from 2.03–2.18 Å. There are four inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with two equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–36°. There are a spread of Ta–O bond distances ranging from 1.96–2.06 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share a cornercorner with one HfO6 octahedra, corners with five TaO6 octahedra, and faces with two equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–36°. There are a spread of Ta–O bond distances ranging from 1.96–2.06 Å. In the third Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent HfO6 octahedra, corners with four TaO6 octahedra, and faces with two equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–46°. There are a spread of Ta–O bond distances ranging from 1.95–2.12 Å. In the fourth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share a cornercorner with one HfO6 octahedra and corners with five TaO6 octahedra. The corner-sharing octahedra tilt angles range from 4–40°. There are a spread of Ta–O bond distances ranging from 1.91–2.12 Å. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Ba2+ and two Ta5+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Ba2+ and two Ta5+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one Hf4+, and one Ta5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Ba2+ and two Ta5+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to one Ba2+ and two equivalent Ta5+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two Ba2+ and two equivalent Hf4+ atoms. In the seventh O2- site, O2- is bonded in a distorted linear geometry to one Ba2+ and two equivalent Ta5+ atoms. In the eighth O2- site, O2- is bonded in a distorted linear geometry to one Ba2+ and two equivalent Ta5+ atoms. In the ninth O2- site, O2- is bonded in a distorted linear geometry to two Ba2+ and two equivalent Ta5+ atoms. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one Hf4+, and one Ta5+ atom. In the eleventh O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ba2+ and two Ta5+ atoms. In the twelfth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ba2+, one Hf4+, and one Ta5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ba2+ and two Ta5+ atoms. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, one Hf4+, and one Ta5+ atom. In the fifteenth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+ and two Ta5+ atoms.