Materials Data on NbFeSe5 by Materials Project
NbFeSe5 crystallizes in the monoclinic P2_1/m space group. The structure is two-dimensional and consists of one NbFeSe5 sheet oriented in the (1, 0, 0) direction. Nb2+ is bonded in a 8-coordinate geometry to eight Se+0.80- atoms. There are a spread of Nb–Se bond distances ranging from 2.65–2.78 Å. Fe2+ is bonded to six Se+0.80- atoms to form edge-sharing FeSe6 octahedra. There are a spread of Fe–Se bond distances ranging from 2.41–2.61 Å. There are five inequivalent Se+0.80- sites. In the first Se+0.80- site, Se+0.80- is bonded in a 2-coordinate geometry to two equivalent Nb2+ atoms. In the second Se+0.80- site, Se+0.80- is bonded in a 2-coordinate geometry to two equivalent Nb2+ atoms. In the third Se+0.80- site, Se+0.80- is bonded to three equivalent Nb2+ and one Fe2+ atom to form a mixture of distorted corner and edge-sharing SeNb3Fe tetrahedra. In the fourth Se+0.80- site, Se+0.80- is bonded in a 3-coordinate geometry to three equivalent Fe2+ atoms. In the fifth Se+0.80- site, Se+0.80- is bonded in a 3-coordinate geometry to one Nb2+ and two equivalent Fe2+ atoms.