DOE OSTI2020
Lu2Mn3Si5 crystallizes in the tetragonal P4/mnc space group. The structure is three-dimensional. Lu3+ is bonded in a 9-coordinate geometry to nine Si+2.40- atoms. There are a spread of Lu–Si bond distances ranging from 2.76–3.08 Å. There are two inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to six Si+2.40- atoms to form a mixture of distorted corner, edge, and face-sharing MnSi6 octahedra. The corner-sharing octahedral tilt angles are 45°. There are a spread of Mn–Si bond distances ranging from 2.35–2.39 Å. In the second Mn2+ site, Mn2+ is bonded in a 6-coordinate geometry to six Si+2.40- atoms. There are four shorter (2.37 Å) and two longer (2.64 Å) Mn–Si bond lengths. There are three inequivalent Si+2.40- sites. In the first Si+2.40- site, Si+2.40- is bonded in a 7-coordinate geometry to three equivalent Lu3+, four Mn2+, and two equivalent Si+2.40- atoms. Both Si–Si bond lengths are 2.50 Å. In the second Si+2.40- site, Si+2.40- is bonded in a 11-coordinate geometry to four equivalent Lu3+, three Mn2+, and four Si+2.40- atoms. Both Si–Si bond lengths are 2.66 Å. In the third Si+2.40- site, Si+2.40- is bonded in a 10-coordinate geometry to four equivalent Lu3+, four equivalent Mn2+, and two equivalent Si+2.40- atoms. There are one shorter (2.65 Å) and one longer (2.68 Å) Si–Si bond lengths.