Materials Data on Fe4Cu2S7 by Materials Project
Fe4Cu2S7 crystallizes in the orthorhombic Pmma space group. The structure is two-dimensional and consists of two Fe4Cu2S7 sheets oriented in the (0, 0, 1) direction. Fe3+ is bonded to four S2- atoms to form a mixture of edge and corner-sharing FeS4 tetrahedra. There are a spread of Fe–S bond distances ranging from 2.12–2.19 Å. Cu1+ is bonded in a 5-coordinate geometry to five S2- atoms. There are a spread of Cu–S bond distances ranging from 2.35–2.58 Å. There are five inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to two equivalent Fe3+ and two equivalent Cu1+ atoms. In the second S2- site, S2- is bonded in a 4-coordinate geometry to four equivalent Fe3+ atoms. In the third S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent Cu1+ atoms. In the fourth S2- site, S2- is bonded in a 4-coordinate geometry to two equivalent Fe3+ and two equivalent Cu1+ atoms. In the fifth S2- site, S2- is bonded in a 4-coordinate geometry to four equivalent Fe3+ atoms.