DOI: 10.17188/1283079
title: Materials Data on Pr2Pb17Se20 by Materials Project

description: Pr2Pb17Se20 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Pr3+ is bonded to six Se2- atoms to form PrSe6 octahedra that share corners with six PbSe6 octahedra, edges with two equivalent PrSe6 octahedra, and edges with eight PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 3–7°. There are a spread of Pr–Se bond distances ranging from 2.93–3.09 Å. There are nine inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to six Se2- atoms to form PbSe6 octahedra that share corners with two equivalent PbSe6 octahedra, corners with three equivalent PrSe6 octahedra, edges with three equivalent PrSe6 octahedra, and edges with seven PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 5–7°. There are a spread of Pb–Se bond distances ranging from 3.05–3.20 Å. In the second Pb2+ site, Pb2+ is bonded to six Se2- atoms to form PbSe6 octahedra that share corners with six PbSe6 octahedra, edges with two equivalent PrSe6 octahedra, and edges with ten PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 2–6°. There are a spread of Pb–Se bond distances ranging from 3.02–3.17 Å. In the third Pb2+ site, Pb2+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 1–6°. There are a spread of Pb–Se bond distances ranging from 3.00–3.21 Å. In the fourth Pb2+ site, Pb2+ is bonded to six Se2- atoms to form PbSe6 octahedra that share a cornercorner with one PrSe6 octahedra, corners with three PbSe6 octahedra, edges with two equivalent PrSe6 octahedra, and edges with nine PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 3–6°. There are a spread of Pb–Se bond distances ranging from 2.93–3.31 Å. In the fifth Pb2+ site, Pb2+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Pb–Se bond distances ranging from 3.04–3.19 Å. In the sixth Pb2+ site, Pb2+ is bonded to six Se2- atoms to form PbSe6 octahedra that share corners with two equivalent PrSe6 octahedra, corners with four PbSe6 octahedra, an edgeedge with one PrSe6 octahedra, and edges with eleven PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. There are a spread of Pb–Se bond distances ranging from 3.03–3.27 Å. In the seventh Pb2+ site, Pb2+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing PbSe6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are two shorter (3.09 Å) and four longer (3.12 Å) Pb–Se bond lengths. In the eighth Pb2+ site, Pb2+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. There are a spread of Pb–Se bond distances ranging from 3.07–3.13 Å. In the ninth Pb2+ site, Pb2+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Pb–Se bond distances ranging from 3.04–3.18 Å. There are ten inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to one Pr3+ and three Pb2+ atoms. In the second Se2- site, Se2- is bonded to two equivalent Pr3+ and three equivalent Pb2+ atoms to form distorted SePr2Pb3 square pyramids that share corners with four SePrPb5 octahedra, edges with four SePrPb5 octahedra, and edges with four equivalent SePr2Pb3 square pyramids. The corner-sharing octahedral tilt angles are 6°. In the third Se2- site, Se2- is bonded to one Pr3+ and five Pb2+ atoms to form distorted SePrPb5 octahedra that share corners with three SePr2Pb4 octahedra, corners with two equivalent SePr2Pb3 square pyramids, edges with seven SePrPb5 octahedra, and edges with three equivalent SePr2Pb3 square pyramids. The corner-sharing octahedra tilt angles range from 3–5°. In the fourth Se2- site, Se2- is bonded to six Pb2+ atoms to form SePb6 octahedra that share corners with four SePb6 octahedra and edges with eleven SePrPb5 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. In the fifth Se2- site, Se2- is bonded to six Pb2+ atoms to form a mixture of edge and corner-sharing SePb6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the sixth Se2- site, Se2- is bonded to two equivalent Pr3+ and four Pb2+ atoms to form distorted SePr2Pb4 octahedra that share corners with four SePrPb5 octahedra, corners with two equivalent SePr2Pb3 square pyramids, edges with nine SePrPb5 octahedra, and an edgeedge with one SePr2Pb3 square pyramid. The corner-sharing octahedra tilt angles range from 1–4°. In the seventh Se2- site, Se2- is bonded to six Pb2+ atoms to form a mixture of edge and corner-sharing SePb6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the eighth Se2- site, Se2- is bonded to six Pb2+ atoms to form a mixture of edge and corner-sharing SePb6 octahedra. The corner-sharing octahedra tilt angles range from 1–5°. In the ninth Se2- site, Se2- is bonded to six Pb2+ atoms to form a mixture of edge and corner-sharing SePb6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the tenth Se2- site, Se2- is bonded to six Pb2+ atoms to form a mixture of edge and corner-sharing SePb6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°.