MgMn4(Si4O11)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 5-coordinate geometry to one O(10), one O(19), one O(2), one O(4), and one O(6) atom. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 5-coordinate geometry to one O(1), one O(12), one O(7), one O(8), and one O(9) atom. In the second Mn site, Mn(2) is bonded to one O(11), one O(16), one O(3), one O(8), and one O(9) atom to form distorted MnO5 trigonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, and  an edgeedge with one Mn(4)O6 octahedra. In the third Mn site, Mn(3) is bonded in a 5-coordinate geometry to one O(12), one O(14), one O(15), one O(20), and one O(7) atom. In the fourth Mn site, Mn(4) is bonded to one O(11), one O(12), one O(14), one O(15), one O(16), and one O(22) atom to form distorted MnO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, and  an edgeedge with one Mn(2)O5 trigonal bipyramid. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(22), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Mn(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 10°. In the second Si site, Si(2) is bonded to one O(10), one O(11), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Mn(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 55°. In the third Si site, Si(3) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(13), one O(14), one O(17), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, and  a cornercorner with one Mn(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 51°. In the fifth Si site, Si(5) is bonded to one O(10), one O(15), one O(6), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Mn(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 65°. In the sixth Si site, Si(6) is bonded to one O(16), one O(17), one O(18), and one O(21) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and  a cornercorner with one Mn(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 58°. In the seventh Si site, Si(7) is bonded to one O(12), one O(13), one O(18), and one O(19) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, and  a cornercorner with one Si(8)O4 tetrahedra. The corner-sharing octahedral tilt angles are 69°. In the eighth Si site, Si(8) is bonded to one O(1), one O(19), one O(20), and one O(21) atom to form corner-sharing SiO4 tetrahedra. There are twenty-two inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mn(1) and one Si(8) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mg(1), one Si(1), and one Si(3) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Mn(2) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mg(1), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Mg(1), one Si(3), and one Si(5) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(3), and one Si(3) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Mn(1), one Mn(2), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(5) atom. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one Mg(1), one Si(2), and one Si(5) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Mn(2), one Mn(4), and one Si(2) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Mn(1), one Mn(3), one Mn(4), and one Si(7) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Si(4) and one Si(7) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Mn(3), one Mn(4), and one Si(4) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Mn(3), one Mn(4), and one Si(5) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal non-coplanar geometry to one Mn(2), one Mn(4), and one Si(6) atom. In the seventeenth O site, O(17) is bonded in a bent 120 degrees geometry to one Si(4) and one Si(6) atom. In the eighteenth O site, O(18) is bonded in a bent 150 degrees geometry to one Si(6) and one Si(7) atom. In the nineteenth O site, O(19) is bonded in a trigonal planar geometry to one Mg(1), one Si(7), and one Si(8) atom. In the twentieth O site, O(20) is bonded in a distorted bent 150 degrees geometry to one Mn(3) and one Si(8) atom. In the twenty-first O site, O(21) is bonded in a distorted bent 150 degrees geometry to one Si(6) and one Si(8) atom. In the twenty-second O site, O(22) is bonded in a linear geometry to one Mn(4) and one Si(1) atom.
MgMn4(Si4O11)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 5-coordinate geometry to one O(10), one O(19), one O(2), one O(4), and one O(6) atom. The Mg(1)-O(10) bond length is 2.18 Å. The Mg(1)-O(19) bond length is 1.99 Å. The Mg(1)-O(2) bond length is 2.14 Å. The Mg(1)-O(4) bond length is 2.10 Å. The Mg(1)-O(6) bond length is 2.13 Å. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 5-coordinate geometry to one O(1), one O(12), one O(7), one O(8), and one O(9) atom. The Mn(1)-O(1) bond length is 2.01 Å. The Mn(1)-O(12) bond length is 2.35 Å. The Mn(1)-O(7) bond length is 2.21 Å. The Mn(1)-O(8) bond length is 2.13 Å. The Mn(1)-O(9) bond length is 2.16 Å. In the second Mn site, Mn(2) is bonded to one O(11), one O(16), one O(3), one O(8), and one O(9) atom to form distorted MnO5 trigonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, and  an edgeedge with one Mn(4)O6 octahedra. The Mn(2)-O(11) bond length is 2.31 Å. The Mn(2)-O(16) bond length is 2.18 Å. The Mn(2)-O(3) bond length is 1.98 Å. The Mn(2)-O(8) bond length is 2.17 Å. The Mn(2)-O(9) bond length is 2.18 Å. In the third Mn site, Mn(3) is bonded in a 5-coordinate geometry to one O(12), one O(14), one O(15), one O(20), and one O(7) atom. The Mn(3)-O(12) bond length is 2.04 Å. The Mn(3)-O(14) bond length is 2.38 Å. The Mn(3)-O(15) bond length is 2.00 Å. The Mn(3)-O(20) bond length is 1.86 Å. The Mn(3)-O(7) bond length is 1.98 Å. In the fourth Mn site, Mn(4) is bonded to one O(11), one O(12), one O(14), one O(15), one O(16), and one O(22) atom to form distorted MnO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, and  an edgeedge with one Mn(2)O5 trigonal bipyramid. The Mn(4)-O(11) bond length is 2.02 Å. The Mn(4)-O(12) bond length is 2.52 Å. The Mn(4)-O(14) bond length is 1.98 Å. The Mn(4)-O(15) bond length is 2.51 Å. The Mn(4)-O(16) bond length is 1.99 Å. The Mn(4)-O(22) bond length is 1.88 Å. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(22), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Mn(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 10°. The Si(1)-O(2) bond length is 1.72 Å. The Si(1)-O(22) bond length is 1.59 Å. The Si(1)-O(3) bond length is 1.58 Å. The Si(1)-O(4) bond length is 1.73 Å. In the second Si site, Si(2) is bonded to one O(10), one O(11), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Mn(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 55°. The Si(2)-O(10) bond length is 1.68 Å. The Si(2)-O(11) bond length is 1.62 Å. The Si(2)-O(4) bond length is 1.67 Å. The Si(2)-O(5) bond length is 1.61 Å. In the third Si site, Si(3) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form corner-sharing SiO4 tetrahedra. The Si(3)-O(2) bond length is 1.66 Å. The Si(3)-O(5) bond length is 1.61 Å. The Si(3)-O(6) bond length is 1.68 Å. The Si(3)-O(7) bond length is 1.62 Å. In the fourth Si site, Si(4) is bonded to one O(13), one O(14), one O(17), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, and  a cornercorner with one Mn(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 51°. The Si(4)-O(13) bond length is 1.67 Å. The Si(4)-O(14) bond length is 1.64 Å. The Si(4)-O(17) bond length is 1.65 Å. The Si(4)-O(8) bond length is 1.62 Å. In the fifth Si site, Si(5) is bonded to one O(10), one O(15), one O(6), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Mn(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 65°. The Si(5)-O(10) bond length is 1.70 Å. The Si(5)-O(15) bond length is 1.62 Å. The Si(5)-O(6) bond length is 1.69 Å. The Si(5)-O(9) bond length is 1.60 Å. In the sixth Si site, Si(6) is bonded to one O(16), one O(17), one O(18), and one O(21) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and  a cornercorner with one Mn(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 58°. The Si(6)-O(16) bond length is 1.65 Å. The Si(6)-O(17) bond length is 1.64 Å. The Si(6)-O(18) bond length is 1.63 Å. The Si(6)-O(21) bond length is 1.63 Å. In the seventh Si site, Si(7) is bonded to one O(12), one O(13), one O(18), and one O(19) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, and  a cornercorner with one Si(8)O4 tetrahedra. The corner-sharing octahedral tilt angles are 69°. The Si(7)-O(12) bond length is 1.62 Å. The Si(7)-O(13) bond length is 1.65 Å. The Si(7)-O(18) bond length is 1.62 Å. The Si(7)-O(19) bond length is 1.68 Å. In the eighth Si site, Si(8) is bonded to one O(1), one O(19), one O(20), and one O(21) atom to form corner-sharing SiO4 tetrahedra. The Si(8)-O(1) bond length is 1.58 Å. The Si(8)-O(19) bond length is 1.73 Å. The Si(8)-O(20) bond length is 1.62 Å. The Si(8)-O(21) bond length is 1.66 Å. There are twenty-two inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mn(1) and one Si(8) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mg(1), one Si(1), and one Si(3) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Mn(2) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mg(1), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Mg(1), one Si(3), and one Si(5) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(3), and one Si(3) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Mn(1), one Mn(2), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(5) atom. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one Mg(1), one Si(2), and one Si(5) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Mn(2), one Mn(4), and one Si(2) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Mn(1), one Mn(3), one Mn(4), and one Si(7) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Si(4) and one Si(7) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Mn(3), one Mn(4), and one Si(4) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Mn(3), one Mn(4), and one Si(5) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal non-coplanar geometry to one Mn(2), one Mn(4), and one Si(6) atom. In the seventeenth O site, O(17) is bonded in a bent 120 degrees geometry to one Si(4) and one Si(6) atom. In the eighteenth O site, O(18) is bonded in a bent 150 degrees geometry to one Si(6) and one Si(7) atom. In the nineteenth O site, O(19) is bonded in a trigonal planar geometry to one Mg(1), one Si(7), and one Si(8) atom. In the twentieth O site, O(20) is bonded in a distorted bent 150 degrees geometry to one Mn(3) and one Si(8) atom. In the twenty-first O site, O(21) is bonded in a distorted bent 150 degrees geometry to one Si(6) and one Si(8) atom. In the twenty-second O site, O(22) is bonded in a linear geometry to one Mn(4) and one Si(1) atom.