Materials Data on HoIO by Materials Project
HoOI crystallizes in the trigonal R-3m space group. The structure is two-dimensional and consists of three HoOI sheets oriented in the (0, 0, 1) direction. Ho3+ is bonded in a 4-coordinate geometry to four equivalent O2- and three equivalent I1- atoms. There are one shorter (2.25 Å) and three longer (2.32 Å) Ho–O bond lengths. All Ho–I bond lengths are 3.14 Å. O2- is bonded to four equivalent Ho3+ atoms to form a mixture of edge and corner-sharing OHo4 tetrahedra. I1- is bonded in a 3-coordinate geometry to three equivalent Ho3+ atoms.