DOE OSTI2020
Ir4Cu2B3 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are four inequivalent Ir sites. In the first Ir site, Ir is bonded in a 8-coordinate geometry to four equivalent Cu and four equivalent B atoms. All Ir–Cu bond lengths are 2.72 Å. All Ir–B bond lengths are 2.21 Å. In the second Ir site, Ir is bonded in a 8-coordinate geometry to four equivalent Cu and four equivalent B atoms. All Ir–Cu bond lengths are 2.72 Å. All Ir–B bond lengths are 2.18 Å. In the third Ir site, Ir is bonded in a 4-coordinate geometry to four B atoms. There are two shorter (2.13 Å) and two longer (2.17 Å) Ir–B bond lengths. In the fourth Ir site, Ir is bonded to six B atoms to form a mixture of distorted corner, edge, and face-sharing IrB6 pentagonal pyramids. All Ir–B bond lengths are 2.25 Å. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded in a 9-coordinate geometry to four equivalent Ir, four equivalent Cu, and one B atom. All Cu–Cu bond lengths are 2.47 Å. The Cu–B bond length is 2.68 Å. In the second Cu site, Cu is bonded in a 8-coordinate geometry to four equivalent Ir and four equivalent Cu atoms. There are three inequivalent B sites. In the first B site, B is bonded in a 6-coordinate geometry to six Ir and one Cu atom. In the second B site, B is bonded in a 6-coordinate geometry to six Ir atoms. In the third B site, B is bonded to six Ir atoms to form a mixture of distorted corner, edge, and face-sharing BIr6 pentagonal pyramids.