Materials Data on ThMnSe3 by Materials Project
ThMnSe3 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Th4+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Th–Se bond distances ranging from 2.95–3.19 Å. Mn2+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing MnSe6 octahedra. The corner-sharing octahedral tilt angles are 48°. There are two shorter (2.57 Å) and four longer (2.78 Å) Mn–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent Th4+ and two equivalent Mn2+ atoms to form distorted corner-sharing SeTh2Mn2 tetrahedra. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to three equivalent Th4+ and two equivalent Mn2+ atoms.