Materials Data on Sr14Nb19O57 by Materials Project

Sr14Nb19O57 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are seven inequivalent Sr sites. In the first Sr site, Sr is bonded to twelve O atoms to form SrO12 cuboctahedra that share corners with four equivalent SrO12 cuboctahedra, faces with four equivalent SrO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.77–2.86 Å. In the second Sr site, Sr is bonded to twelve O atoms to form SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, and faces with eight NbO6 octahedra. There are four shorter (2.86 Å) and eight longer (2.87 Å) Sr–O bond lengths. In the third Sr site, Sr is bonded to twelve O atoms to form SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, and faces with eight NbO6 octahedra. There are four shorter (2.86 Å) and eight longer (2.87 Å) Sr–O bond lengths. In the fourth Sr site, Sr is bonded to twelve O atoms to form SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.81–2.90 Å. In the fifth Sr site, Sr is bonded to twelve O atoms to form SrO12 cuboctahedra that share corners with four equivalent SrO12 cuboctahedra, faces with four equivalent SrO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.73–2.86 Å. In the sixth Sr site, Sr is bonded to twelve O atoms to form distorted SrO12 cuboctahedra that share corners with eight SrO12 cuboctahedra, faces with five SrO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.59–3.08 Å. In the seventh Sr site, Sr is bonded to twelve O atoms to form SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, and faces with eight NbO6 octahedra. There are eight shorter (2.86 Å) and four longer (2.88 Å) Sr–O bond lengths. There are ten inequivalent Nb sites. In the first Nb site, Nb is bonded to six O atoms to form distorted NbO6 octahedra that share corners with six NbO6 octahedra and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–18°. There are a spread of Nb–O bond distances ranging from 1.88–2.23 Å. In the second Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Nb–O bond distances ranging from 1.97–2.08 Å. In the third Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–13°. There are a spread of Nb–O bond distances ranging from 1.95–2.15 Å. In the fourth Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–9°. There are five shorter (2.03 Å) and one longer (2.05 Å) Nb–O bond lengths. In the fifth Nb site, Nb is bonded to six O atoms to form distorted NbO6 octahedra that share corners with six NbO6 octahedra and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–22°. There are a spread of Nb–O bond distances ranging from 1.83–2.29 Å. In the sixth Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with eight SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are a spread of Nb–O bond distances ranging from 1.94–2.08 Å. In the seventh Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with eight SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are four shorter (2.02 Å) and two longer (2.05 Å) Nb–O bond lengths. In the eighth Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with eight SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.02 Å) and two longer (2.04 Å) Nb–O bond lengths. In the ninth Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with eight SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–O bond distances ranging from 2.02–2.05 Å. In the tenth 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 SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.02 Å) and two longer (2.04 Å) Nb–O bond lengths. There are twenty inequivalent O sites. In the first O site, O is bonded in a distorted see-saw-like geometry to two equivalent Sr and two equivalent Nb atoms. In the second O site, O is bonded in a linear geometry to two Nb atoms. In the third O site, O is bonded to four equivalent Sr and two Nb atoms to form distorted OSr4Nb2 octahedra that share corners with four equivalent OSr4Nb2 octahedra, corners with eight equivalent OSr2Nb2 trigonal pyramids, edges with four equivalent OSr4Nb2 octahedra, and faces with four equivalent OSr2Nb2 trigonal pyramids. The corner-sharing octahedral tilt angles are 3°. In the fourth O site, O is bonded in a linear geometry to two Nb atoms. In the fifth O site, O is bonded in a distorted linear geometry to four equivalent Sr and two Nb atoms. In the sixth O site, O is bonded in a linear geometry to two equivalent Nb atoms. In the seventh O site, O is bonded in a 6-coordinate geometry to four equivalent Sr and two Nb atoms. In the eighth O site, O is bonded to four equivalent Sr and two Nb atoms to form a mixture of distorted edge and corner-sharing OSr4Nb2 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the ninth O site, O is bonded to four equivalent Sr and two Nb atoms to form a mixture of distorted edge and corner-sharing OSr4Nb2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the tenth O site, O is bonded to four equivalent Sr and two Nb atoms to form a mixture of distorted edge and corner-sharing OSr4Nb2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the eleventh O site, O is bonded to four equivalent Sr and two Nb atoms to form a mixture of distorted edge and corner-sharing OSr4Nb2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the twelfth O site, O is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr and two equivalent Nb atoms. In the thirteenth O site, O is bonded to two equivalent Sr and two equivalent Nb atoms to form distorted OSr2Nb2 trigonal pyramids that share corners with four equivalent OSr4Nb2 octahedra, corners with four equivalent OSr2Nb2 trigonal pyramids, edges with four equivalent OSr2Nb2 trigonal pyramids, and faces with two equivalent OSr4Nb2 octahedra. The corner-sharing octahedral tilt angles are 57°. In the fourteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr and two equivalent Nb atoms. In the fifteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr and two equivalent Nb atoms. In the sixteenth O site, O is bonded in a distorted linear geometry to four Sr and two equivalent Nb atoms. In the seventeenth O site, O is bonded in a distorted linear geometry to four Sr and two equivalent Nb atoms. In the eighteenth O site, O is bonded in a distorted linear geometry to four Sr and two equivalent Nb atoms. In the nineteenth O site, O is bonded in a distorted linear geometry to four Sr and two equivalent Nb atoms. In the twentieth O site, O is bonded in a distorted linear geometry to four equivalent Sr and two equivalent Nb atoms.