DOI: 10.17188/1207539
title: Materials Data on Ca(Nd2Se3)4 by Materials Project

description: Ca(Nd2Se3)4 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. Ca2+ is bonded to eight Se2- atoms to form distorted CaSe8 hexagonal bipyramids that share corners with eight NdSe8 hexagonal bipyramids, edges with four NdSe8 hexagonal bipyramids, and faces with eight NdSe8 hexagonal bipyramids. There are a spread of Ca–Se bond distances ranging from 3.00–3.23 Å. There are eight inequivalent Nd+2.75+ sites. In the first Nd+2.75+ site, Nd+2.75+ is bonded to eight Se2- atoms to form distorted NdSe8 hexagonal bipyramids that share corners with two equivalent CaSe8 hexagonal bipyramids, corners with six NdSe8 hexagonal bipyramids, edges with four NdSe8 hexagonal bipyramids, a faceface with one CaSe8 hexagonal bipyramid, and faces with seven NdSe8 hexagonal bipyramids. There are a spread of Nd–Se bond distances ranging from 2.99–3.20 Å. In the second Nd+2.75+ site, Nd+2.75+ is bonded to eight Se2- atoms to form distorted NdSe8 hexagonal bipyramids that share a cornercorner with one CaSe8 hexagonal bipyramid, corners with seven NdSe8 hexagonal bipyramids, an edgeedge with one CaSe8 hexagonal bipyramid, edges with three NdSe8 hexagonal bipyramids, a faceface with one CaSe8 hexagonal bipyramid, and faces with seven NdSe8 hexagonal bipyramids. There are a spread of Nd–Se bond distances ranging from 3.01–3.22 Å. In the third Nd+2.75+ site, Nd+2.75+ is bonded to eight Se2- atoms to form distorted NdSe8 hexagonal bipyramids that share corners with two equivalent CaSe8 hexagonal bipyramids, corners with six NdSe8 hexagonal bipyramids, edges with four NdSe8 hexagonal bipyramids, a faceface with one CaSe8 hexagonal bipyramid, and faces with seven NdSe8 hexagonal bipyramids. There are a spread of Nd–Se bond distances ranging from 3.00–3.20 Å. In the fourth Nd+2.75+ site, Nd+2.75+ is bonded to eight Se2- atoms to form distorted NdSe8 hexagonal bipyramids that share a cornercorner with one CaSe8 hexagonal bipyramid, corners with seven NdSe8 hexagonal bipyramids, edges with four NdSe8 hexagonal bipyramids, a faceface with one CaSe8 hexagonal bipyramid, and faces with seven NdSe8 hexagonal bipyramids. There are a spread of Nd–Se bond distances ranging from 2.99–3.20 Å. In the fifth Nd+2.75+ site, Nd+2.75+ is bonded to eight Se2- atoms to form distorted NdSe8 hexagonal bipyramids that share corners with eight NdSe8 hexagonal bipyramids, edges with two equivalent CaSe8 hexagonal bipyramids, edges with two NdSe8 hexagonal bipyramids, and faces with eight NdSe8 hexagonal bipyramids. There are a spread of Nd–Se bond distances ranging from 3.00–3.21 Å. In the sixth Nd+2.75+ site, Nd+2.75+ is bonded to eight Se2- atoms to form distorted NdSe8 hexagonal bipyramids that share corners with eight NdSe8 hexagonal bipyramids, edges with four NdSe8 hexagonal bipyramids, faces with two equivalent CaSe8 hexagonal bipyramids, and faces with six NdSe8 hexagonal bipyramids. There are a spread of Nd–Se bond distances ranging from 3.01–3.20 Å. In the seventh Nd+2.75+ site, Nd+2.75+ is bonded to eight Se2- atoms to form distorted NdSe8 hexagonal bipyramids that share a cornercorner with one CaSe8 hexagonal bipyramid, corners with seven NdSe8 hexagonal bipyramids, edges with four NdSe8 hexagonal bipyramids, a faceface with one CaSe8 hexagonal bipyramid, and faces with seven NdSe8 hexagonal bipyramids. There are a spread of Nd–Se bond distances ranging from 3.00–3.21 Å. In the eighth Nd+2.75+ site, Nd+2.75+ is bonded to eight Se2- atoms to form distorted NdSe8 hexagonal bipyramids that share a cornercorner with one CaSe8 hexagonal bipyramid, corners with seven NdSe8 hexagonal bipyramids, an edgeedge with one CaSe8 hexagonal bipyramid, edges with three NdSe8 hexagonal bipyramids, a faceface with one CaSe8 hexagonal bipyramid, and faces with seven NdSe8 hexagonal bipyramids. There are a spread of Nd–Se bond distances ranging from 2.99–3.22 Å. There are twelve inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to six Nd+2.75+ atoms to form a mixture of distorted face, edge, and corner-sharing SeNd6 octahedra. The corner-sharing octahedra tilt angles range from 17–50°. In the second Se2- site, Se2- is bonded to one Ca2+ and five Nd+2.75+ atoms to form a mixture of distorted face, edge, and corner-sharing SeCaNd5 octahedra. The corner-sharing octahedra tilt angles range from 18–50°. In the third Se2- site, Se2- is bonded to one Ca2+ and five Nd+2.75+ atoms to form distorted SeCaNd5 octahedra that share corners with fifteen SeNd6 octahedra, edges with six SeCaNd5 octahedra, and faces with five SeNd6 octahedra. The corner-sharing octahedra tilt angles range from 17–50°. In the fourth Se2- site, Se2- is bonded to one Ca2+ and five Nd+2.75+ atoms to form distorted SeCaNd5 octahedra that share corners with fifteen SeNd6 octahedra, edges with six SeNd6 octahedra, and faces with five SeCaNd5 octahedra. The corner-sharing octahedra tilt angles range from 17–50°. In the fifth Se2- site, Se2- is bonded to six Nd+2.75+ atoms to form distorted SeNd6 octahedra that share corners with fifteen SeCaNd5 octahedra, edges with six SeNd6 octahedra, and faces with five SeNd6 octahedra. The corner-sharing octahedra tilt angles range from 16–50°. In the sixth Se2- site, Se2- is bonded to one Ca2+ and five Nd+2.75+ atoms to form distorted SeCaNd5 octahedra that share corners with fifteen SeNd6 octahedra, edges with six SeCaNd5 octahedra, and faces with five SeNd6 octahedra. The corner-sharing octahedra tilt angles range from 17–50°. In the seventh Se2- site, Se2- is bonded to one Ca2+ and five Nd+2.75+ atoms to form distorted SeCaNd5 octahedra that share corners with fifteen SeNd6 octahedra, edges with six SeNd6 octahedra, and faces with five SeCaNd5 octahedra. The corner-sharing octahedra tilt angles range from 17–50°. In the eighth Se2- site, Se2- is bonded to one Ca2+ and five Nd+2.75+ atoms to form distorted SeCaNd5 octahedra that share corners with fifteen SeNd6 octahedra, edges with six SeNd6 octahedra, and faces with five SeCaNd5 octahedra. The corner-sharing octahedra tilt angles range from 17–50°. In the ninth Se2- site, Se2- is bonded to one Ca2+ and five Nd+2.75+ atoms to form distorted SeCaNd5 octahedra that share corners with fifteen SeNd6 octahedra, edges with six SeNd6 octahedra, and faces with five SeCaNd5 octahedra. The corner-sharing octahedra tilt angles range from 17–50°. In the tenth Se2- site, Se2- is bonded to one Ca2+ and five Nd+2.75+ atoms to form distorted SeCaNd5 octahedra that share corners with fifteen SeNd6 octahedra, edges with six SeCaNd5 octahedra, and faces with five SeCaNd5 octahedra. The corner-sharing octahedra tilt angles range from 17–50°. In the eleventh Se2- site, Se2- is bonded to six Nd+2.75+ atoms to form distorted SeNd6 octahedra that share corners with fifteen SeNd6 octahedra, edges with six SeCaNd5 octahedra, and faces with five SeNd6 octahedra. The corner-sharing octahedra tilt angles range from 16–50°. In the twelfth Se2- site, Se2- is bonded to six Nd+2.75+ atoms to form distorted SeNd6 octahedra that share corners with fifteen SeNd6 octahedra, edges with six SeCaNd5 octahedra, and faces with five SeNd6 octahedra. The corner-sharing octahedra tilt angles range from 16–50°.