V2Si4O11 crystallizes in the triclinic P-1 space group. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(7), one O(8), one O(9), and two equivalent O(11) atoms to form distorted VO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one V(1)O6 octahedra, and edges with three equivalent V(2)O6 octahedra. In the second V site, V(2) is bonded to one O(11), one O(3), one O(8), one O(9), and two equivalent O(7) atoms to form distorted VO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one V(2)O6 octahedra, and edges with three equivalent V(1)O6 octahedra. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one V(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-50°. 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 V(2)O6 octahedra, corners with two equivalent V(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-66°. 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 SiO4 tetrahedra that share  a cornercorner with one V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-67°. In the fourth Si site, Si(4) is bonded to one O(10), one O(6), one O(8), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-62°. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one V(1) and one Si(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(3) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one V(2) and one Si(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to 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 bent 120 degrees geometry to one Si(3) and one Si(4) atom. In the seventh O site, O(7) is bonded to one V(1), two equivalent V(2), and one Si(3) atom to form a mixture of distorted edge and corner-sharing OV3Si tetrahedra. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one V(1), one V(2), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one V(1), one V(2), and one Si(4) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(4) atom. In the eleventh O site, O(11) is bonded to one V(2), two equivalent V(1), and one Si(2) atom to form a mixture of distorted edge and corner-sharing OV3Si tetrahedra.
V2Si4O11 crystallizes in the triclinic P-1 space group. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(7), one O(8), one O(9), and two equivalent O(11) atoms to form distorted VO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one V(1)O6 octahedra, and edges with three equivalent V(2)O6 octahedra. The V(1)-O(1) bond length is 1.87 Å. The V(1)-O(7) bond length is 2.20 Å. The V(1)-O(8) bond length is 2.23 Å. The V(1)-O(9) bond length is 2.06 Å. There is one shorter (2.12 Å) and one longer (2.23 Å) V(1)-O(11) bond length. In the second V site, V(2) is bonded to one O(11), one O(3), one O(8), one O(9), and two equivalent O(7) atoms to form distorted VO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one V(2)O6 octahedra, and edges with three equivalent V(1)O6 octahedra. The V(2)-O(11) bond length is 2.33 Å. The V(2)-O(3) bond length is 1.86 Å. The V(2)-O(8) bond length is 2.03 Å. The V(2)-O(9) bond length is 2.22 Å. There is one shorter (2.14 Å) and one longer (2.32 Å) V(2)-O(7) bond length. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one V(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-50°. The Si(1)-O(1) bond length is 1.60 Å. The Si(1)-O(2) bond length is 1.65 Å. The Si(1)-O(3) bond length is 1.63 Å. The Si(1)-O(4) bond length is 1.65 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 V(2)O6 octahedra, corners with two equivalent V(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-66°. The Si(2)-O(10) bond length is 1.64 Å. The Si(2)-O(11) bond length is 1.68 Å. The Si(2)-O(4) bond length is 1.61 Å. The Si(2)-O(5) bond length is 1.60 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 SiO4 tetrahedra that share  a cornercorner with one V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-67°. The Si(3)-O(2) bond length is 1.61 Å. The Si(3)-O(5) bond length is 1.60 Å. The Si(3)-O(6) bond length is 1.63 Å. The Si(3)-O(7) bond length is 1.69 Å. In the fourth Si site, Si(4) is bonded to one O(10), one O(6), one O(8), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-62°. The Si(4)-O(10) bond length is 1.63 Å. The Si(4)-O(6) bond length is 1.63 Å. The Si(4)-O(8) bond length is 1.66 Å. The Si(4)-O(9) bond length is 1.64 Å. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one V(1) and one Si(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(3) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one V(2) and one Si(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to 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 bent 120 degrees geometry to one Si(3) and one Si(4) atom. In the seventh O site, O(7) is bonded to one V(1), two equivalent V(2), and one Si(3) atom to form a mixture of distorted edge and corner-sharing OV3Si tetrahedra. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one V(1), one V(2), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one V(1), one V(2), and one Si(4) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(4) atom. In the eleventh O site, O(11) is bonded to one V(2), two equivalent V(1), and one Si(2) atom to form a mixture of distorted edge and corner-sharing OV3Si tetrahedra.