Mg2Ti is beta-derived structured and crystallizes in the orthorhombic Pmmn space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(3); six Mg(2,2); and four equivalent Ti(1) atoms to form MgMg8Ti4 cuboctahedra that share corners with eight equivalent Ti(1)Mg9Ti3 cuboctahedra; corners with ten equivalent Mg(2)Mg8Ti4 cuboctahedra; edges with four equivalent Mg(3)Mg6Ti6 cuboctahedra; edges with four Mg(2,2)Mg8Ti4 cuboctahedra; edges with four equivalent Ti(1)Mg9Ti3 cuboctahedra; edges with six equivalent Mg(1)Mg8Ti4 cuboctahedra; faces with two equivalent Mg(1)Mg8Ti4 cuboctahedra; faces with four equivalent Mg(3)Mg6Ti6 cuboctahedra; faces with six Mg(2,2)Mg8Ti4 cuboctahedra; and faces with eight equivalent Ti(1)Mg9Ti3 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(3), three equivalent Mg(1), three equivalent Mg(2), and four equivalent Ti(1) atoms to form distorted MgMg8Ti4 cuboctahedra that share corners with four equivalent Mg(3)Mg6Ti6 cuboctahedra; corners with four equivalent Ti(1)Mg9Ti3 cuboctahedra; corners with five equivalent Mg(1)Mg8Ti4 cuboctahedra; corners with five equivalent Mg(2)Mg8Ti4 cuboctahedra; edges with two equivalent Mg(3)Mg6Ti6 cuboctahedra; edges with two equivalent Mg(1)Mg8Ti4 cuboctahedra; edges with six equivalent Ti(1)Mg9Ti3 cuboctahedra; edges with eight Mg(2,2)Mg8Ti4 cuboctahedra; faces with three equivalent Mg(1)Mg8Ti4 cuboctahedra; faces with four equivalent Mg(3)Mg6Ti6 cuboctahedra; faces with five equivalent Mg(2)Mg8Ti4 cuboctahedra; and faces with eight equivalent Ti(1)Mg9Ti3 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), four equivalent Mg(2), and six equivalent Ti(1) atoms to form distorted MgMg6Ti6 cuboctahedra that share corners with eight equivalent Mg(2)Mg8Ti4 cuboctahedra; corners with ten equivalent Ti(1)Mg9Ti3 cuboctahedra; edges with four equivalent Mg(1)Mg8Ti4 cuboctahedra; edges with four Mg(2,2)Mg8Ti4 cuboctahedra; edges with four equivalent Ti(1)Mg9Ti3 cuboctahedra; edges with six equivalent Mg(3)Mg6Ti6 cuboctahedra; faces with two equivalent Mg(3)Mg6Ti6 cuboctahedra; faces with four equivalent Mg(1)Mg8Ti4 cuboctahedra; faces with six equivalent Ti(1)Mg9Ti3 cuboctahedra; and faces with eight Mg(2,2)Mg8Ti4 cuboctahedra. In the fourth Mg site, Mg(2) is bonded to two equivalent Mg(3), three equivalent Mg(1), three equivalent Mg(2), and four equivalent Ti(1) atoms to form distorted MgMg8Ti4 cuboctahedra that share corners with four equivalent Mg(3)Mg6Ti6 cuboctahedra; corners with four equivalent Ti(1)Mg9Ti3 cuboctahedra; corners with five equivalent Mg(1)Mg8Ti4 cuboctahedra; corners with five equivalent Mg(2)Mg8Ti4 cuboctahedra; edges with two equivalent Mg(3)Mg6Ti6 cuboctahedra; edges with two equivalent Mg(1)Mg8Ti4 cuboctahedra; edges with six equivalent Ti(1)Mg9Ti3 cuboctahedra; edges with eight Mg(2,2)Mg8Ti4 cuboctahedra; faces with three equivalent Mg(1)Mg8Ti4 cuboctahedra; faces with four equivalent Mg(3)Mg6Ti6 cuboctahedra; faces with five Mg(2,2)Mg8Ti4 cuboctahedra; and faces with eight equivalent Ti(1)Mg9Ti3 cuboctahedra. Ti(1) is bonded to two equivalent Mg(1), three equivalent Mg(3), four equivalent Mg(2), and three equivalent Ti(1) atoms to form TiMg9Ti3 cuboctahedra that share corners with four equivalent Mg(1)Mg8Ti4 cuboctahedra; corners with four equivalent Mg(2)Mg8Ti4 cuboctahedra; corners with five equivalent Mg(3)Mg6Ti6 cuboctahedra; corners with five equivalent Ti(1)Mg9Ti3 cuboctahedra; edges with two equivalent Mg(3)Mg6Ti6 cuboctahedra; edges with two equivalent Mg(1)Mg8Ti4 cuboctahedra; edges with six Mg(2,2)Mg8Ti4 cuboctahedra; edges with eight equivalent Ti(1)Mg9Ti3 cuboctahedra; faces with three equivalent Mg(3)Mg6Ti6 cuboctahedra; faces with four equivalent Mg(1)Mg8Ti4 cuboctahedra; faces with five equivalent Ti(1)Mg9Ti3 cuboctahedra; and faces with eight Mg(2,2)Mg8Ti4 cuboctahedra.
Mg2Ti is beta-derived structured and crystallizes in the orthorhombic Pmmn space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(3); six Mg(2,2); and four equivalent Ti(1) atoms to form MgMg8Ti4 cuboctahedra that share corners with eight equivalent Ti(1)Mg9Ti3 cuboctahedra; corners with ten equivalent Mg(2)Mg8Ti4 cuboctahedra; edges with four equivalent Mg(3)Mg6Ti6 cuboctahedra; edges with four Mg(2,2)Mg8Ti4 cuboctahedra; edges with four equivalent Ti(1)Mg9Ti3 cuboctahedra; edges with six equivalent Mg(1)Mg8Ti4 cuboctahedra; faces with two equivalent Mg(1)Mg8Ti4 cuboctahedra; faces with four equivalent Mg(3)Mg6Ti6 cuboctahedra; faces with six Mg(2,2)Mg8Ti4 cuboctahedra; and faces with eight equivalent Ti(1)Mg9Ti3 cuboctahedra. Both Mg(1)-Mg(3) bond lengths are 3.10 Å. There are two shorter (3.01 Å) and four longer (3.10 Å) Mg(1)-Mg(2,2) bond lengths. There are two shorter (3.08 Å) and two longer (3.20 Å) Mg(1)-Ti(1) bond lengths. In the second Mg site, Mg(2) is bonded to two equivalent Mg(3), three equivalent Mg(1), three equivalent Mg(2), and four equivalent Ti(1) atoms to form distorted MgMg8Ti4 cuboctahedra that share corners with four equivalent Mg(3)Mg6Ti6 cuboctahedra; corners with four equivalent Ti(1)Mg9Ti3 cuboctahedra; corners with five equivalent Mg(1)Mg8Ti4 cuboctahedra; corners with five equivalent Mg(2)Mg8Ti4 cuboctahedra; edges with two equivalent Mg(3)Mg6Ti6 cuboctahedra; edges with two equivalent Mg(1)Mg8Ti4 cuboctahedra; edges with six equivalent Ti(1)Mg9Ti3 cuboctahedra; edges with eight Mg(2,2)Mg8Ti4 cuboctahedra; faces with three equivalent Mg(1)Mg8Ti4 cuboctahedra; faces with four equivalent Mg(3)Mg6Ti6 cuboctahedra; faces with five equivalent Mg(2)Mg8Ti4 cuboctahedra; and faces with eight equivalent Ti(1)Mg9Ti3 cuboctahedra. There is one shorter (3.08 Å) and one longer (3.23 Å) Mg(2)-Mg(3) bond length. There are two shorter (3.03 Å) and one longer (3.15 Å) Mg(2)-Mg(2) bond length. There are a spread of Mg(2)-Ti(1) bond distances ranging from 3.03-3.17 Å. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), four equivalent Mg(2), and six equivalent Ti(1) atoms to form distorted MgMg6Ti6 cuboctahedra that share corners with eight equivalent Mg(2)Mg8Ti4 cuboctahedra; corners with ten equivalent Ti(1)Mg9Ti3 cuboctahedra; edges with four equivalent Mg(1)Mg8Ti4 cuboctahedra; edges with four Mg(2,2)Mg8Ti4 cuboctahedra; edges with four equivalent Ti(1)Mg9Ti3 cuboctahedra; edges with six equivalent Mg(3)Mg6Ti6 cuboctahedra; faces with two equivalent Mg(3)Mg6Ti6 cuboctahedra; faces with four equivalent Mg(1)Mg8Ti4 cuboctahedra; faces with six equivalent Ti(1)Mg9Ti3 cuboctahedra; and faces with eight Mg(2,2)Mg8Ti4 cuboctahedra. There are four shorter (3.04 Å) and two longer (3.05 Å) Mg(3)-Ti(1) bond lengths. In the fourth Mg site, Mg(2) is bonded to two equivalent Mg(3), three equivalent Mg(1), three equivalent Mg(2), and four equivalent Ti(1) atoms to form distorted MgMg8Ti4 cuboctahedra that share corners with four equivalent Mg(3)Mg6Ti6 cuboctahedra; corners with four equivalent Ti(1)Mg9Ti3 cuboctahedra; corners with five equivalent Mg(1)Mg8Ti4 cuboctahedra; corners with five equivalent Mg(2)Mg8Ti4 cuboctahedra; edges with two equivalent Mg(3)Mg6Ti6 cuboctahedra; edges with two equivalent Mg(1)Mg8Ti4 cuboctahedra; edges with six equivalent Ti(1)Mg9Ti3 cuboctahedra; edges with eight Mg(2,2)Mg8Ti4 cuboctahedra; faces with three equivalent Mg(1)Mg8Ti4 cuboctahedra; faces with four equivalent Mg(3)Mg6Ti6 cuboctahedra; faces with five Mg(2,2)Mg8Ti4 cuboctahedra; and faces with eight equivalent Ti(1)Mg9Ti3 cuboctahedra. There is one shorter (3.08 Å) and one longer (3.23 Å) Mg(2)-Mg(3) bond length. There are two shorter (3.03 Å) and one longer (3.15 Å) Mg(2)-Mg(2) bond length. There are a spread of Mg(2)-Ti(1) bond distances ranging from 3.03-3.17 Å. Ti(1) is bonded to two equivalent Mg(1), three equivalent Mg(3), four equivalent Mg(2), and three equivalent Ti(1) atoms to form TiMg9Ti3 cuboctahedra that share corners with four equivalent Mg(1)Mg8Ti4 cuboctahedra; corners with four equivalent Mg(2)Mg8Ti4 cuboctahedra; corners with five equivalent Mg(3)Mg6Ti6 cuboctahedra; corners with five equivalent Ti(1)Mg9Ti3 cuboctahedra; edges with two equivalent Mg(3)Mg6Ti6 cuboctahedra; edges with two equivalent Mg(1)Mg8Ti4 cuboctahedra; edges with six Mg(2,2)Mg8Ti4 cuboctahedra; edges with eight equivalent Ti(1)Mg9Ti3 cuboctahedra; faces with three equivalent Mg(3)Mg6Ti6 cuboctahedra; faces with four equivalent Mg(1)Mg8Ti4 cuboctahedra; faces with five equivalent Ti(1)Mg9Ti3 cuboctahedra; and faces with eight Mg(2,2)Mg8Ti4 cuboctahedra. There are two shorter (3.02 Å) and one longer (3.09 Å) Ti(1)-Ti(1) bond length.