DOE OSTI2020
Ba(NdS2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.19–3.42 Å. There are two inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Nd–S bond distances ranging from 2.80–3.39 Å. In the second Nd3+ site, Nd3+ is bonded to six S2- atoms to form edge-sharing NdS6 octahedra. There are a spread of Nd–S bond distances ranging from 2.77–2.95 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Ba2+ and three Nd3+ atoms. In the second S2- site, S2- is bonded to two equivalent Ba2+ and four Nd3+ atoms to form distorted SBa2Nd4 octahedra that share corners with four equivalent SBa2Nd3 square pyramids, edges with four equivalent SBa2Nd4 octahedra, and a faceface with one SBa2Nd3 square pyramid. In the third S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Ba2+ and three Nd3+ atoms. In the fourth S2- site, S2- is bonded to two equivalent Ba2+ and three equivalent Nd3+ atoms to form distorted SBa2Nd3 square pyramids that share corners with four equivalent SBa2Nd4 octahedra, edges with four equivalent SBa2Nd3 square pyramids, and a faceface with one SBa2Nd4 octahedra. The corner-sharing octahedra tilt angles range from 56–62°.