DOI: 10.17188/1716023
title: Materials Data on Ca2AlPbOF8 by Materials Project

description: Ca2AlPbOF8 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Ca sites. In the first Ca site, Ca is bonded in a distorted body-centered cubic geometry to eight F atoms. There are a spread of Ca–F bond distances ranging from 2.30–2.66 Å. In the second Ca site, Ca is bonded in a 8-coordinate geometry to one O and seven F atoms. The Ca–O bond length is 2.48 Å. There are a spread of Ca–F bond distances ranging from 2.28–2.57 Å. In the third Ca site, Ca is bonded in a distorted body-centered cubic geometry to eight F atoms. There are a spread of Ca–F bond distances ranging from 2.29–2.69 Å. In the fourth Ca site, Ca is bonded in a distorted body-centered cubic geometry to one O and seven F atoms. The Ca–O bond length is 2.50 Å. There are a spread of Ca–F bond distances ranging from 2.33–2.51 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded to six F atoms to form AlF6 octahedra that share corners with three equivalent PbO2F3 square pyramids. There are a spread of Al–F bond distances ranging from 1.81–1.84 Å. In the second Al site, Al is bonded to one O and five F atoms to form AlOF5 octahedra that share a cornercorner with one PbO2F3 square pyramid. The Al–O bond length is 1.92 Å. There are a spread of Al–F bond distances ranging from 1.82–1.90 Å. There are two inequivalent Pb sites. In the first Pb site, Pb is bonded to two O and three F atoms to form PbO2F3 square pyramids that share corners with four AlF6 octahedra. The corner-sharing octahedra tilt angles range from 36–63°. There are one shorter (1.98 Å) and one longer (2.02 Å) Pb–O bond lengths. There are a spread of Pb–F bond distances ranging from 2.22–2.43 Å. In the second Pb site, Pb is bonded in a 5-coordinate geometry to one O and four F atoms. The Pb–O bond length is 2.60 Å. There are a spread of Pb–F bond distances ranging from 2.31–2.56 Å. There are two inequivalent O sites. In the first O site, O is bonded in a distorted trigonal planar geometry to two Ca and one Pb atom. In the second O site, O is bonded in a distorted bent 120 degrees geometry to one Al and two Pb atoms. There are sixteen inequivalent F sites. In the first F site, F is bonded to four Ca atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the second F site, F is bonded to four Ca atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the third F site, F is bonded in a trigonal non-coplanar geometry to two Ca and one Al atom. In the fourth F site, F is bonded in a trigonal non-coplanar geometry to two Ca and one Al atom. In the fifth F site, F is bonded in a 1-coordinate geometry to two Ca and one Al atom. In the sixth F site, F is bonded in a 2-coordinate geometry to two Ca and one Al atom. In the seventh F site, F is bonded to four Ca atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the eighth F site, F is bonded to four Ca atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the ninth F site, F is bonded in a distorted single-bond geometry to one Al and one Pb atom. In the tenth F site, F is bonded in a distorted single-bond geometry to one Al and one Pb atom. In the eleventh F site, F is bonded in a distorted single-bond geometry to one Al and one Pb atom. In the twelfth F site, F is bonded in a distorted single-bond geometry to one Al and one Pb atom. In the thirteenth F site, F is bonded in a 1-coordinate geometry to two Ca and one Al atom. In the fourteenth F site, F is bonded in a 1-coordinate geometry to two Ca and one Al atom. In the fifteenth F site, F is bonded in a trigonal planar geometry to two Ca and one Pb atom. In the sixteenth F site, F is bonded in a 1-coordinate geometry to one Al and two Pb atoms.