Materials Data on LaPb6BrO7 by Materials Project
LaPb6O7Br crystallizes in the orthorhombic Cmcm space group. The structure is two-dimensional and consists of two LaPb6O7Br sheets oriented in the (0, 1, 0) direction. La3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.54 Å) and four longer (2.63 Å) La–O bond lengths. There are three inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded in a 5-coordinate geometry to three O2- and two equivalent Br1- atoms. There are one shorter (2.26 Å) and two longer (2.33 Å) Pb–O bond lengths. Both Pb–Br bond lengths are 3.39 Å. In the second Pb2+ site, Pb2+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Pb–O bond distances ranging from 2.21–2.55 Å. In the third Pb2+ site, Pb2+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are two shorter (2.22 Å) and one longer (2.26 Å) Pb–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent La3+ and two Pb2+ atoms to form a mixture of edge and corner-sharing OLa2Pb2 tetrahedra. In the second O2- site, O2- is bonded to one La3+ and three Pb2+ atoms to form a mixture of distorted edge and corner-sharing OLaPb3 tetrahedra. In the third O2- site, O2- is bonded in a distorted see-saw-like geometry to four Pb2+ atoms. Br1- is bonded in a distorted square co-planar geometry to four equivalent Pb2+ atoms.