Materials Data on Ca2F by Materials Project
Ca2F crystallizes in the monoclinic Cm space group. The structure is two-dimensional and consists of four Ca2F sheets oriented in the (1, 0, 0) direction. In two of the Ca2F sheets, there are six inequivalent Ca sites. In the first Ca site, Ca is bonded in a linear geometry to two F atoms. There are one shorter (2.38 Å) and one longer (2.42 Å) Ca–F bond lengths. In the second Ca site, Ca is bonded in a trigonal non-coplanar geometry to three F atoms. All Ca–F bond lengths are 2.36 Å. In the third Ca site, Ca is bonded in a water-like geometry to two equivalent F atoms. Both Ca–F bond lengths are 2.41 Å. In the fourth Ca site, Ca is bonded in a bent 120 degrees geometry to two equivalent F atoms. Both Ca–F bond lengths are 2.36 Å. In the fifth Ca site, Ca is bonded in a single-bond geometry to one F atom. The Ca–F bond length is 2.36 Å. In the sixth Ca site, Ca is bonded in a linear geometry to two F atoms. There are one shorter (2.35 Å) and one longer (2.36 Å) Ca–F bond lengths. There are three inequivalent F sites. In the first F site, F is bonded to four Ca atoms to form corner-sharing FCa4 tetrahedra. In the second F site, F is bonded to four Ca atoms to form corner-sharing FCa4 tetrahedra. In the third F site, F is bonded to four Ca atoms to form corner-sharing FCa4 tetrahedra. In two of the Ca2F sheets, there are four inequivalent Ca sites. In the first Ca site, Ca is bonded in a linear geometry to two F atoms. Both Ca–F bond lengths are 2.36 Å. In the second Ca site, Ca is bonded in a linear geometry to two F atoms. There are one shorter (2.35 Å) and one longer (2.36 Å) Ca–F bond lengths. In the third Ca site, Ca is bonded in a bent 120 degrees geometry to two equivalent F atoms. Both Ca–F bond lengths are 2.37 Å. In the fourth Ca site, Ca is bonded in a bent 120 degrees geometry to two equivalent F atoms. Both Ca–F bond lengths are 2.37 Å. There are two inequivalent F sites. In the first F site, F is bonded to four Ca atoms to form corner-sharing FCa4 tetrahedra. In the second F site, F is bonded to four Ca atoms to form corner-sharing FCa4 tetrahedra.