Materials Data on LaNb2HO7 by Materials Project
HLaNb2O7 crystallizes in the tetragonal P4/mmm space group. The structure is two-dimensional and consists of one hydrogen molecule and one LaNb2O7 sheet oriented in the (0, 0, 1) direction. In the LaNb2O7 sheet, La3+ is bonded to twelve O2- atoms to form a mixture of corner and face-sharing LaO12 cuboctahedra. There are eight shorter (2.69 Å) and four longer (2.77 Å) La–O bond lengths. Nb5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Nb–O bond distances ranging from 1.76–2.38 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent La3+ and two equivalent Nb5+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one Nb5+ atom. In the third O2- site, O2- is bonded to four equivalent La3+ and two equivalent Nb5+ atoms to form a mixture of distorted corner and edge-sharing OLa4Nb2 octahedra. The corner-sharing octahedral tilt angles are 0°.