Materials Data on CaMg2 by Materials Project
Mg2Ca is Hexagonal Laves structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ca is bonded in a 12-coordinate geometry to four equivalent Ca and twelve Mg atoms. There are one shorter (3.76 Å) and three longer (3.82 Å) Ca–Ca bond lengths. There are a spread of Ca–Mg bond distances ranging from 3.60–3.67 Å. There are two inequivalent Mg sites. In the first Mg site, Mg is bonded to six equivalent Ca and six equivalent Mg atoms to form a mixture of corner, edge, and face-sharing MgCa6Mg6 cuboctahedra. All Mg–Mg bond lengths are 3.10 Å. In the second Mg site, Mg is bonded to six equivalent Ca and six Mg atoms to form a mixture of corner, edge, and face-sharing MgCa6Mg6 cuboctahedra. There are two shorter (3.09 Å) and two longer (3.17 Å) Mg–Mg bond lengths.