DOE OSTI2019
Nd2Sn3(PbS4)3 crystallizes in the orthorhombic Pmc2_1 space group. The structure is three-dimensional. there are two inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Nd–S bond distances ranging from 2.90–3.26 Å. In the second Nd3+ site, Nd3+ is bonded to seven S2- atoms to form distorted NdS7 pentagonal bipyramids that share corners with two equivalent SnS6 octahedra, edges with four SnS6 octahedra, and edges with two equivalent NdS7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 50°. There are a spread of Nd–S bond distances ranging from 2.87–2.89 Å. There are three inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Pb–S bond distances ranging from 2.97–3.36 Å. In the second Pb2+ site, Pb2+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Pb–S bond distances ranging from 2.96–3.20 Å. In the third Pb2+ site, Pb2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Pb–S bond distances ranging from 2.89–3.38 Å. There are three inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to six S2- atoms to form SnS6 octahedra that share edges with two equivalent SnS6 octahedra and edges with two equivalent NdS7 pentagonal bipyramids. There are a spread of Sn–S bond distances ranging from 2.54–2.66 Å. In the second Sn4+ site, Sn4+ is bonded to six S2- atoms to form SnS6 octahedra that share corners with two equivalent NdS7 pentagonal bipyramids, edges with two equivalent SnS6 octahedra, and edges with two equivalent NdS7 pentagonal bipyramids. There are a spread of Sn–S bond distances ranging from 2.54–2.64 Å. In the third Sn4+ site, Sn4+ is bonded to five S2- atoms to form corner-sharing SnS5 trigonal bipyramids. There are a spread of Sn–S bond distances ranging from 2.44–2.57 Å. There are twelve inequivalent S2- sites. In the first S2- site, S2- is bonded in a 5-coordinate geometry to four Pb2+ and one Sn4+ atom. In the second S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Nd3+, two equivalent Pb2+, and one Sn4+ atom. In the third S2- site, S2- is bonded in a 3-coordinate geometry to two equivalent Nd3+, two equivalent Pb2+, and one Sn4+ atom. In the fourth S2- site, S2- is bonded in a distorted single-bond geometry to four Pb2+ and one Sn4+ atom. In the fifth S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Nd3+, two equivalent Pb2+, and one Sn4+ atom. In the sixth S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Nd3+, two equivalent Pb2+, and one Sn4+ atom. In the seventh S2- site, S2- is bonded in a 3-coordinate geometry to two equivalent Nd3+, two equivalent Pb2+, and one Sn4+ atom. In the eighth S2- site, S2- is bonded in a 4-coordinate geometry to one Nd3+, one Pb2+, and two equivalent Sn4+ atoms. In the ninth S2- site, S2- is bonded in a 4-coordinate geometry to one Nd3+, one Pb2+, and two equivalent Sn4+ atoms. In the tenth S2- site, S2- is bonded in a 4-coordinate geometry to one Nd3+, one Pb2+, and two equivalent Sn4+ atoms. In the eleventh S2- site, S2- is bonded in a 4-coordinate geometry to one Nd3+, one Pb2+, and two equivalent Sn4+ atoms. In the twelfth S2- site, S2- is bonded in a 2-coordinate geometry to one Nd3+, one Pb2+, and two equivalent Sn4+ atoms.