Materials Data on Ca2LaF7 by Materials Project
Ca2LaF7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Ca–F bond distances ranging from 2.35–2.81 Å. In the second Ca2+ site, Ca2+ is bonded in a body-centered cubic geometry to eight F1- atoms. There are a spread of Ca–F bond distances ranging from 2.26–2.51 Å. La3+ is bonded in a 11-coordinate geometry to eleven F1- atoms. There are a spread of La–F bond distances ranging from 2.32–2.69 Å. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded to four Ca2+ atoms to form FCa4 tetrahedra that share corners with twelve FCa4 tetrahedra and edges with six FCa3La tetrahedra. In the second F1- site, F1- is bonded in a 4-coordinate geometry to one Ca2+ and three equivalent La3+ atoms. In the third F1- site, F1- is bonded to three equivalent Ca2+ and one La3+ atom to form a mixture of distorted corner and edge-sharing FCa3La tetrahedra. In the fourth F1- site, F1- is bonded to three equivalent Ca2+ and one La3+ atom to form a mixture of corner and edge-sharing FCa3La tetrahedra. In the fifth F1- site, F1- is bonded to four Ca2+ atoms to form FCa4 tetrahedra that share corners with twelve FCa3La tetrahedra and edges with six FCa4 tetrahedra. In the sixth F1- site, F1- is bonded in a trigonal planar geometry to three equivalent La3+ atoms. In the seventh F1- site, F1- is bonded in a 1-coordinate geometry to one Ca2+ and three equivalent La3+ atoms.