MgCa crystallizes in the orthorhombic Amm2 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted body-centered cubic geometry to two equivalent Mg(1), two equivalent Mg(2), and four equivalent Mg(3) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to two equivalent Mg(1), two equivalent Mg(3), and four equivalent Mg(2) atoms. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to two equivalent Mg(3) and four equivalent Mg(1) atoms. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), four equivalent Ca(3), and two equivalent Mg(2) atoms. In the second Mg site, Mg(2) is bonded in a body-centered cubic geometry to two equivalent Ca(1), four equivalent Ca(2), and two equivalent Mg(1) atoms. In the third Mg site, Mg(3) is bonded in a body-centered cubic geometry to two equivalent Ca(2), two equivalent Ca(3), and four equivalent Ca(1) atoms.
MgCa crystallizes in the orthorhombic Amm2 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted body-centered cubic geometry to two equivalent Mg(1), two equivalent Mg(2), and four equivalent Mg(3) atoms. Both Ca(1)-Mg(1) bond lengths are 3.67 Å. Both Ca(1)-Mg(2) bond lengths are 3.53 Å. All Ca(1)-Mg(3) bond lengths are 3.44 Å. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to two equivalent Mg(1), two equivalent Mg(3), and four equivalent Mg(2) atoms. Both Ca(2)-Mg(1) bond lengths are 3.85 Å. Both Ca(2)-Mg(3) bond lengths are 3.28 Å. All Ca(2)-Mg(2) bond lengths are 3.44 Å. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to two equivalent Mg(3) and four equivalent Mg(1) atoms. Both Ca(3)-Mg(3) bond lengths are 3.37 Å. All Ca(3)-Mg(1) bond lengths are 3.49 Å. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), four equivalent Ca(3), and two equivalent Mg(2) atoms. Both Mg(1)-Mg(2) bond lengths are 3.17 Å. In the second Mg site, Mg(2) is bonded in a body-centered cubic geometry to two equivalent Ca(1), four equivalent Ca(2), and two equivalent Mg(1) atoms. In the third Mg site, Mg(3) is bonded in a body-centered cubic geometry to two equivalent Ca(2), two equivalent Ca(3), and four equivalent Ca(1) atoms.