Materials Data on CaMg2 by Materials Project

Abstract

Mg2Ca crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded to four Ca and eight Mg atoms to form a mixture of distorted face and corner-sharing CaCa4Mg8 cuboctahedra. There are two shorter (3.45 Å) and two longer (3.71 Å) Ca–Ca bond lengths. There are a spread of Ca–Mg bond distances ranging from 3.37–3.63 Å. In the second Ca site, Ca is bonded in a 12-coordinate geometry to four Ca and eight Mg atoms. Both Ca–Ca bond lengths are 3.45 Å. There are a spread of Ca–Mg bond distances ranging from 3.25–3.58 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to three Ca and six Mg atoms. There are a spread of Mg–Mg bond distances ranging from 3.38–3.51 Å. In the second Mg site, Mg is bonded in a 12-coordinate geometry to five Ca and five Mg atoms. There are one shorter (3.22 Å) and two longer (3.45 Å) Mg–Mg bond lengths. In the third Mg site, Mg is bonded in a 12-coordinate geometry to four Ca and six Mg atoms. There are two shorter (3.28 Å) and two longer (3.45 Å) Mg–Mg bond lengths. In the fourth Mg site, Mg is bonded in a 11-coordinate geometry to four Ca and seven Mg atoms. Both Mg–Mg bond lengths are 3.45 Å.