Materials Data on Er2US3O2 by Materials Project
UEr2O2S3 crystallizes in the tetragonal I4mm space group. The structure is three-dimensional. U4+ is bonded in a 4-coordinate geometry to four equivalent S2- and four equivalent O2- atoms. All U–S bond lengths are 2.97 Å. All U–O bond lengths are 2.26 Å. There are two inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of corner and edge-sharing ErS6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are a spread of Er–S bond distances ranging from 2.65–2.77 Å. In the second Er3+ site, Er3+ is bonded in a 4-coordinate geometry to four equivalent S2- and four equivalent O2- atoms. All Er–S bond lengths are 2.95 Å. All Er–O bond lengths are 2.31 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 1-coordinate geometry to four equivalent U4+ and one Er3+ atom. In the second S2- site, S2- is bonded in a 1-coordinate geometry to five Er3+ atoms. In the third S2- site, S2- is bonded in a rectangular see-saw-like geometry to four equivalent Er3+ atoms. O2- is bonded to two equivalent U4+ and two equivalent Er3+ atoms to form a mixture of corner and edge-sharing OEr2U2 tetrahedra.