RbMg14Ti crystallizes in the orthorhombic Amm2 space group. Rb(1) is bonded to two equivalent Mg(7); four Mg(3,3,3); four Mg(5,5,5); and two equivalent Ti(1) atoms to form RbMg10Ti2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with six equivalent Rb(1)Mg10Ti2 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Ti(1)Rb2Mg10 cuboctahedra; edges with four Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra; edges with four equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Ti(1)Rb2Mg10 cuboctahedra; faces with four Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra; and faces with six equivalent Mg(6)Mg11Ti cuboctahedra. There are twelve inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2); two equivalent Mg(6); four Mg(4,4); and four Mg(5,5,5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Rb(1)Mg10Ti2 cuboctahedra; corners with six equivalent Mg(1)Mg12 cuboctahedra; corners with eight Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with four equivalent Mg(6)Mg11Ti cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Ti(1)Rb2Mg10 cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(7)RbMg11 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1); two equivalent Mg(7); four Mg(4,4); and four Mg(5,5,5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Ti(1)Rb2Mg10 cuboctahedra; corners with six equivalent Mg(2)Mg12 cuboctahedra; corners with eight Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with four equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Rb(1)Mg10Ti2 cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(6)Mg11Ti cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Rb(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Ti(1) atoms to form distorted MgRb2Mg8Ti2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with six Mg(3,3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Rb(1)Mg10Ti2 cuboctahedra; edges with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Ti(1)Rb2Mg10 cuboctahedra; edges with four equivalent Mg(6)Mg11Ti cuboctahedra; edges with four equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Rb(1)Mg10Ti2 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; and faces with two equivalent Ti(1)Rb2Mg10 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1); two equivalent Mg(2); two equivalent Mg(4); two Mg(5,5); two equivalent Mg(6); and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Rb(1)Mg10Ti2 cuboctahedra, corners with four equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra, corners with four equivalent Ti(1)Rb2Mg10 cuboctahedra, corners with six equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(6)Mg11Ti cuboctahedra, edges with four equivalent Mg(7)RbMg11 cuboctahedra, faces with two equivalent Mg(6)Mg11Ti cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra, and faces with two equivalent Mg(7)RbMg11 cuboctahedra. In the fifth Mg site, Mg(3) is bonded to two equivalent Rb(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Ti(1) atoms to form distorted MgRb2Mg8Ti2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with six Mg(3,3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Rb(1)Mg10Ti2 cuboctahedra; edges with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Ti(1)Rb2Mg10 cuboctahedra; edges with four equivalent Mg(6)Mg11Ti cuboctahedra; edges with four equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Rb(1)Mg10Ti2 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; and faces with two equivalent Ti(1)Rb2Mg10 cuboctahedra. In the sixth Mg site, Mg(5) is bonded in a 12-coordinate geometry to one Rb(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ti(1) atom. In the seventh Mg site, Mg(5) is bonded in a 12-coordinate geometry to one Rb(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ti(1) atom. In the eighth Mg site, Mg(5) is bonded in a 12-coordinate geometry to one Rb(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ti(1) atom. In the ninth Mg site, Mg(6) is bonded to one Mg(1); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(7); four Mg(5,5); and one Ti(1) atom to form distorted MgMg11Ti cuboctahedra that share corners with four equivalent Mg(7)RbMg11 cuboctahedra; corners with six equivalent Mg(6)Mg11Ti cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with two equivalent Mg(7)RbMg11 cuboctahedra; edges with two equivalent Ti(1)Rb2Mg10 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with four Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Ti(1)Rb2Mg10 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; faces with three equivalent Rb(1)Mg10Ti2 cuboctahedra; and faces with three equivalent Mg(2)Mg12 cuboctahedra. In the tenth Mg site, Mg(7) is bonded to one Rb(1); one Mg(2); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(6); and four Mg(5,5) atoms to form distorted MgRbMg11 cuboctahedra that share corners with four equivalent Mg(6)Mg11Ti cuboctahedra; corners with six equivalent Mg(7)RbMg11 cuboctahedra; edges with two equivalent Rb(1)Mg10Ti2 cuboctahedra; edges with two equivalent Mg(6)Mg11Ti cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with four Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra;  a faceface with one Rb(1)Mg10Ti2 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; faces with three equivalent Mg(1)Mg12 cuboctahedra; and faces with three equivalent Ti(1)Rb2Mg10 cuboctahedra. In the eleventh Mg site, Mg(3) is bonded to two equivalent Rb(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Ti(1) atoms to form distorted MgRb2Mg8Ti2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with six Mg(3,3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Rb(1)Mg10Ti2 cuboctahedra; edges with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Ti(1)Rb2Mg10 cuboctahedra; edges with four equivalent Mg(6)Mg11Ti cuboctahedra; edges with four equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Rb(1)Mg10Ti2 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; and faces with two equivalent Ti(1)Rb2Mg10 cuboctahedra. In the twelfth Mg site, Mg(4) is bonded to two equivalent Mg(1); two equivalent Mg(2); two equivalent Mg(4); two Mg(5,5); two equivalent Mg(6); and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Rb(1)Mg10Ti2 cuboctahedra; corners with four equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; corners with four equivalent Ti(1)Rb2Mg10 cuboctahedra; corners with six Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with four equivalent Mg(6)Mg11Ti cuboctahedra; edges with four equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; and faces with two equivalent Mg(7)RbMg11 cuboctahedra. Ti(1) is bonded to two equivalent Rb(1); two equivalent Mg(6); four Mg(3,3,3); and four Mg(5,5,5) atoms to form TiRb2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with six equivalent Ti(1)Rb2Mg10 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Rb(1)Mg10Ti2 cuboctahedra; edges with four equivalent Mg(6)Mg11Ti cuboctahedra; edges with four Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra; faces with two equivalent Rb(1)Mg10Ti2 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with four Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra; and faces with six equivalent Mg(7)RbMg11 cuboctahedra.
RbMg14Ti crystallizes in the orthorhombic Amm2 space group. Rb(1) is bonded to two equivalent Mg(7); four Mg(3,3,3); four Mg(5,5,5); and two equivalent Ti(1) atoms to form RbMg10Ti2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with six equivalent Rb(1)Mg10Ti2 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Ti(1)Rb2Mg10 cuboctahedra; edges with four Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra; edges with four equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Ti(1)Rb2Mg10 cuboctahedra; faces with four Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra; and faces with six equivalent Mg(6)Mg11Ti cuboctahedra. Both Rb(1)-Mg(7) bond lengths are 3.37 Å. There are two shorter (3.25 Å) and two longer (3.28 Å) Rb(1)-Mg(3,3,3) bond lengths. All Rb(1)-Mg(5,5,5) bond lengths are 3.36 Å. Both Rb(1)-Ti(1) bond lengths are 3.31 Å. There are twelve inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2); two equivalent Mg(6); four Mg(4,4); and four Mg(5,5,5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Rb(1)Mg10Ti2 cuboctahedra; corners with six equivalent Mg(1)Mg12 cuboctahedra; corners with eight Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with four equivalent Mg(6)Mg11Ti cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Ti(1)Rb2Mg10 cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(7)RbMg11 cuboctahedra. Both Mg(1)-Mg(2) bond lengths are 3.31 Å. Both Mg(1)-Mg(6) bond lengths are 3.25 Å. There are two shorter (3.25 Å) and two longer (3.28 Å) Mg(1)-Mg(4,4) bond lengths. All Mg(1)-Mg(5,5,5) bond lengths are 3.13 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1); two equivalent Mg(7); four Mg(4,4); and four Mg(5,5,5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Ti(1)Rb2Mg10 cuboctahedra; corners with six equivalent Mg(2)Mg12 cuboctahedra; corners with eight Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with four equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Rb(1)Mg10Ti2 cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(6)Mg11Ti cuboctahedra. Both Mg(2)-Mg(7) bond lengths are 3.15 Å. There are two shorter (3.25 Å) and two longer (3.28 Å) Mg(2)-Mg(4,4) bond lengths. All Mg(2)-Mg(5,5,5) bond lengths are 3.22 Å. In the third Mg site, Mg(3) is bonded to two equivalent Rb(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Ti(1) atoms to form distorted MgRb2Mg8Ti2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with six Mg(3,3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Rb(1)Mg10Ti2 cuboctahedra; edges with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Ti(1)Rb2Mg10 cuboctahedra; edges with four equivalent Mg(6)Mg11Ti cuboctahedra; edges with four equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Rb(1)Mg10Ti2 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; and faces with two equivalent Ti(1)Rb2Mg10 cuboctahedra. There is one shorter (3.30 Å) and one longer (3.32 Å) Mg(3)-Mg(3) bond length. Both Mg(3)-Mg(5,5) bond lengths are 3.26 Å. Both Mg(3)-Mg(6) bond lengths are 3.20 Å. Both Mg(3)-Mg(7) bond lengths are 3.34 Å. There is one shorter (3.13 Å) and one longer (3.40 Å) Mg(3)-Ti(1) bond length. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1); two equivalent Mg(2); two equivalent Mg(4); two Mg(5,5); two equivalent Mg(6); and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Rb(1)Mg10Ti2 cuboctahedra, corners with four equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra, corners with four equivalent Ti(1)Rb2Mg10 cuboctahedra, corners with six equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(6)Mg11Ti cuboctahedra, edges with four equivalent Mg(7)RbMg11 cuboctahedra, faces with two equivalent Mg(6)Mg11Ti cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra, and faces with two equivalent Mg(7)RbMg11 cuboctahedra. There is one shorter (3.27 Å) and one longer (3.35 Å) Mg(4)-Mg(4) bond length. Both Mg(4)-Mg(5,5) bond lengths are 3.15 Å. Both Mg(4)-Mg(6) bond lengths are 3.30 Å. Both Mg(4)-Mg(7) bond lengths are 3.10 Å. In the fifth Mg site, Mg(3) is bonded to two equivalent Rb(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Ti(1) atoms to form distorted MgRb2Mg8Ti2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with six Mg(3,3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Rb(1)Mg10Ti2 cuboctahedra; edges with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Ti(1)Rb2Mg10 cuboctahedra; edges with four equivalent Mg(6)Mg11Ti cuboctahedra; edges with four equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Rb(1)Mg10Ti2 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; and faces with two equivalent Ti(1)Rb2Mg10 cuboctahedra. There is one shorter (3.30 Å) and one longer (3.32 Å) Mg(3)-Mg(3) bond length. Both Mg(3)-Mg(5,5) bond lengths are 3.26 Å. Both Mg(3)-Mg(6) bond lengths are 3.20 Å. Both Mg(3)-Mg(7) bond lengths are 3.34 Å. There is one shorter (3.13 Å) and one longer (3.40 Å) Mg(3)-Ti(1) bond length. In the sixth Mg site, Mg(5) is bonded in a 12-coordinate geometry to one Rb(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ti(1) atom. There is one shorter (3.13 Å) and one longer (3.49 Å) Mg(5)-Mg(5) bond length. There is one shorter (3.20 Å) and one longer (3.34 Å) Mg(5)-Mg(6) bond length. There is one shorter (3.14 Å) and one longer (3.40 Å) Mg(5)-Mg(7) bond length. The Mg(5)-Ti(1) bond length is 3.22 Å. In the seventh Mg site, Mg(5) is bonded in a 12-coordinate geometry to one Rb(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ti(1) atom. There is one shorter (3.13 Å) and one longer (3.49 Å) Mg(5)-Mg(5) bond length. There is one shorter (3.20 Å) and one longer (3.34 Å) Mg(5)-Mg(6) bond length. There is one shorter (3.14 Å) and one longer (3.40 Å) Mg(5)-Mg(7) bond length. The Mg(5)-Ti(1) bond length is 3.22 Å. In the eighth Mg site, Mg(5) is bonded in a 12-coordinate geometry to one Rb(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ti(1) atom. The Mg(5)-Mg(4) bond length is 3.15 Å. There is one shorter (3.20 Å) and one longer (3.34 Å) Mg(5)-Mg(6) bond length. There is one shorter (3.14 Å) and one longer (3.40 Å) Mg(5)-Mg(7) bond length. The Mg(5)-Ti(1) bond length is 3.22 Å. In the ninth Mg site, Mg(6) is bonded to one Mg(1); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(7); four Mg(5,5); and one Ti(1) atom to form distorted MgMg11Ti cuboctahedra that share corners with four equivalent Mg(7)RbMg11 cuboctahedra; corners with six equivalent Mg(6)Mg11Ti cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with two equivalent Mg(7)RbMg11 cuboctahedra; edges with two equivalent Ti(1)Rb2Mg10 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with four Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Ti(1)Rb2Mg10 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; faces with three equivalent Rb(1)Mg10Ti2 cuboctahedra; and faces with three equivalent Mg(2)Mg12 cuboctahedra. The Mg(6)-Mg(4) bond length is 3.30 Å. Both Mg(6)-Mg(7) bond lengths are 3.32 Å. The Mg(6)-Ti(1) bond length is 3.21 Å. In the tenth Mg site, Mg(7) is bonded to one Rb(1); one Mg(2); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(6); and four Mg(5,5) atoms to form distorted MgRbMg11 cuboctahedra that share corners with four equivalent Mg(6)Mg11Ti cuboctahedra; corners with six equivalent Mg(7)RbMg11 cuboctahedra; edges with two equivalent Rb(1)Mg10Ti2 cuboctahedra; edges with two equivalent Mg(6)Mg11Ti cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with four Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra;  a faceface with one Rb(1)Mg10Ti2 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; faces with three equivalent Mg(1)Mg12 cuboctahedra; and faces with three equivalent Ti(1)Rb2Mg10 cuboctahedra. The Mg(7)-Mg(4) bond length is 3.10 Å. In the eleventh Mg site, Mg(3) is bonded to two equivalent Rb(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Ti(1) atoms to form distorted MgRb2Mg8Ti2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with six Mg(3,3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Rb(1)Mg10Ti2 cuboctahedra; edges with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; edges with two equivalent Ti(1)Rb2Mg10 cuboctahedra; edges with four equivalent Mg(6)Mg11Ti cuboctahedra; edges with four equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Rb(1)Mg10Ti2 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; faces with two equivalent Mg(7)RbMg11 cuboctahedra; and faces with two equivalent Ti(1)Rb2Mg10 cuboctahedra. Both Mg(3)-Mg(5,5) bond lengths are 3.26 Å. Both Mg(3)-Mg(6) bond lengths are 3.20 Å. Both Mg(3)-Mg(7) bond lengths are 3.34 Å. There is one shorter (3.13 Å) and one longer (3.40 Å) Mg(3)-Ti(1) bond length. In the twelfth Mg site, Mg(4) is bonded to two equivalent Mg(1); two equivalent Mg(2); two equivalent Mg(4); two Mg(5,5); two equivalent Mg(6); and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Rb(1)Mg10Ti2 cuboctahedra; corners with four equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; corners with four equivalent Ti(1)Rb2Mg10 cuboctahedra; corners with six Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with four equivalent Mg(6)Mg11Ti cuboctahedra; edges with four equivalent Mg(7)RbMg11 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Rb2Mg8Ti2 cuboctahedra; and faces with two equivalent Mg(7)RbMg11 cuboctahedra. Both Mg(4)-Mg(5,5) bond lengths are 3.15 Å. Ti(1) is bonded to two equivalent Rb(1); two equivalent Mg(6); four Mg(3,3,3); and four Mg(5,5,5) atoms to form TiRb2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with six equivalent Ti(1)Rb2Mg10 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Rb(1)Mg10Ti2 cuboctahedra; edges with four equivalent Mg(6)Mg11Ti cuboctahedra; edges with four Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra; faces with two equivalent Rb(1)Mg10Ti2 cuboctahedra; faces with two equivalent Mg(6)Mg11Ti cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with four Mg(3,3,3)Rb2Mg8Ti2 cuboctahedra; and faces with six equivalent Mg(7)RbMg11 cuboctahedra.