Materials Data on Tm2MgSe4 by Materials Project

Dataset · Wed Jan 16 04:00:00 EST 2019

DOI:https://doi.org/10.17188/1685646· OSTI ID:1685646

MgTm2Se4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Mg2+ is bonded to four Se2- atoms to form MgSe4 trigonal pyramids that share corners with three equivalent TmSe6 octahedra and a faceface with one TmSe6 octahedra. The corner-sharing octahedra tilt angles range from 11–66°. There are a spread of Mg–Se bond distances ranging from 2.46–2.64 Å. There are two inequivalent Tm3+ sites. In the first Tm3+ site, Tm3+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Tm–Se bond distances ranging from 2.75–3.27 Å. In the second Tm3+ site, Tm3+ is bonded to six Se2- atoms to form distorted TmSe6 octahedra that share corners with three equivalent MgSe4 trigonal pyramids, edges with two equivalent TmSe6 octahedra, and a faceface with one MgSe4 trigonal pyramid. There are a spread of Tm–Se bond distances ranging from 2.67–2.93 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to one Mg2+ and four Tm3+ atoms. In the second Se2- site, Se2- is bonded in a T-shaped geometry to one Mg2+ and two Tm3+ atoms. In the third Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Tm3+ atoms.

• Research Organization: LBNL Materials Project; Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Contributing Organization: The Materials Project; MIT; UC Berkeley; Duke; U Louvain
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 1685646
• Report Number(s): mp-1232135
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Mg-Se-Tm
Tm2MgSe4
crystal structure