Materials Data on TmSeO3F by Materials Project
TmSeO3F crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Tm3+ is bonded in a 8-coordinate geometry to six O2- and two equivalent F1- atoms. There are a spread of Tm–O bond distances ranging from 2.26–2.63 Å. Both Tm–F bond lengths are 2.18 Å. Se4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.71–1.78 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to three equivalent Tm3+ and one Se4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Tm3+ and one Se4+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Tm3+ and one Se4+ atom. F1- is bonded in a distorted bent 120 degrees geometry to two equivalent Tm3+ atoms.