Materials Data on Ba5Ca2Nb3O15 by Materials Project

Abstract

Ba5Ca2Nb3O15 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. there are two inequivalent Ba sites. In the first Ba site, Ba is bonded to twelve O atoms to form BaO12 cuboctahedra that share corners with twelve equivalent BaO12 cuboctahedra, faces with six BaO12 cuboctahedra, faces with four equivalent CaO6 octahedra, and faces with four equivalent NbO6 octahedra. There are a spread of Ba–O bond distances ranging from 3.01–3.12 Å. In the second Ba site, Ba is bonded to twelve O atoms to form BaO12 cuboctahedra that share corners with twelve BaO12 cuboctahedra, faces with six BaO12 cuboctahedra, faces with three equivalent CaO6 octahedra, and faces with five NbO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.94–3.15 Å. Ca is bonded to six O atoms to form CaO6 octahedra that share corners with six NbO6 octahedra and faces with eight BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–8°. There are a spread of Ca–O bond distances ranging from 2.28–2.32 Å. There are three inequivalent Nb sites. In the first Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with eight equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.02 Å) and two longer (2.10 Å) Nb–O bond lengths. In the second Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share a cornercorner with one NbO6 octahedra, corners with five equivalent CaO6 octahedra, and faces with eight BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–8°. There are a spread of Nb–O bond distances ranging from 1.92–2.36 Å. In the third Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four equivalent CaO6 octahedra, and faces with eight equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (1.98 Å) and two longer (2.16 Å) Nb–O bond lengths. There are seven inequivalent O sites. In the first O site, O is bonded in a distorted linear geometry to four Ba, one Ca, and one Nb atom. In the second O site, O is bonded in a distorted linear geometry to four equivalent Ba and two Nb atoms. In the third O site, O is bonded in a distorted linear geometry to four equivalent Ba, one Ca, and one Nb atom. In the fourth O site, O is bonded to four equivalent Ba and two Nb atoms to form a mixture of distorted corner and face-sharing OBa4Nb2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fifth O site, O is bonded in a distorted linear geometry to four equivalent Ba, one Ca, and one Nb atom. In the sixth O site, O is bonded in a distorted linear geometry to four Ba, one Ca, and one Nb atom. In the seventh O site, O is bonded in a distorted linear geometry to four Ba, one Ca, and one Nb atom.