Li4V2Si(PO6)2 crystallizes in the monoclinic Cc space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(5) atom. In the second Li site, Li(2) is bonded to one O(10), one O(11), one O(2), one O(3), one O(6), and one O(7) atom to form distorted LiO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  a faceface with one V(1)O6 octahedra, and  a faceface with one V(2)O6 octahedra. In the third Li site, Li(3) is bonded in a 6-coordinate geometry to one O(10), one O(3), one O(4), one O(6), one O(7), and one O(9) atom. In the fourth Li site, Li(4) is bonded in a 4-coordinate geometry to one O(10), one O(11), one O(12), and one O(8) atom. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(11), one O(12), one O(3), one O(5), one O(6), and one O(9) atom to form VO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  a faceface with one Li(2)O6 octahedra. In the second V site, V(2) is bonded to one O(1), one O(10), one O(2), one O(4), one O(7), and one O(8) atom to form VO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  a faceface with one Li(2)O6 octahedra. Si(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Li(2)O6 octahedra, corners with two equivalent V(1)O6 octahedra, and corners with two equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-47°. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(12), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Li(2)O6 octahedra, corners with two equivalent V(1)O6 octahedra, and corners with two equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-46°. In the second P site, P(2) is bonded to one O(10), one O(11), one O(8), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Li(2)O6 octahedra, corners with two equivalent V(1)O6 octahedra, and corners with two equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-45°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(1), one V(2), and one P(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one V(2), and one Si(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Li(1), one Li(2), one Li(3), one V(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Li(3), one V(2), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Li(1), one V(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Li(3), one V(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal pyramidal geometry to one Li(2), one Li(3), one V(2), and one P(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Li(4), one V(2), and one P(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Li(3), one V(1), and one P(2) atom. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Li(3), one Li(4), one V(2), and one P(2) atom. In the eleventh O site, O(11) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Li(4), one V(1), and one P(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Li(4), one V(1), and one P(1) atom.
Li4V2Si(PO6)2 crystallizes in the monoclinic Cc space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(5) atom. The Li(1)-O(1) bond length is 2.48 Å. The Li(1)-O(2) bond length is 2.06 Å. The Li(1)-O(3) bond length is 2.11 Å. The Li(1)-O(5) bond length is 2.09 Å. In the second Li site, Li(2) is bonded to one O(10), one O(11), one O(2), one O(3), one O(6), and one O(7) atom to form distorted LiO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  a faceface with one V(1)O6 octahedra, and  a faceface with one V(2)O6 octahedra. The Li(2)-O(10) bond length is 2.30 Å. The Li(2)-O(11) bond length is 2.35 Å. The Li(2)-O(2) bond length is 2.12 Å. The Li(2)-O(3) bond length is 2.06 Å. The Li(2)-O(6) bond length is 2.30 Å. The Li(2)-O(7) bond length is 2.20 Å. In the third Li site, Li(3) is bonded in a 6-coordinate geometry to one O(10), one O(3), one O(4), one O(6), one O(7), and one O(9) atom. The Li(3)-O(10) bond length is 2.65 Å. The Li(3)-O(3) bond length is 2.54 Å. The Li(3)-O(4) bond length is 2.13 Å. The Li(3)-O(6) bond length is 2.13 Å. The Li(3)-O(7) bond length is 2.14 Å. The Li(3)-O(9) bond length is 2.50 Å. In the fourth Li site, Li(4) is bonded in a 4-coordinate geometry to one O(10), one O(11), one O(12), and one O(8) atom. The Li(4)-O(10) bond length is 2.11 Å. The Li(4)-O(11) bond length is 2.07 Å. The Li(4)-O(12) bond length is 2.37 Å. The Li(4)-O(8) bond length is 2.25 Å. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(11), one O(12), one O(3), one O(5), one O(6), and one O(9) atom to form VO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  a faceface with one Li(2)O6 octahedra. The V(1)-O(11) bond length is 2.09 Å. The V(1)-O(12) bond length is 2.05 Å. The V(1)-O(3) bond length is 2.03 Å. The V(1)-O(5) bond length is 1.93 Å. The V(1)-O(6) bond length is 2.08 Å. The V(1)-O(9) bond length is 2.04 Å. In the second V site, V(2) is bonded to one O(1), one O(10), one O(2), one O(4), one O(7), and one O(8) atom to form VO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  a faceface with one Li(2)O6 octahedra. The V(2)-O(1) bond length is 2.00 Å. The V(2)-O(10) bond length is 2.08 Å. The V(2)-O(2) bond length is 2.02 Å. The V(2)-O(4) bond length is 1.95 Å. The V(2)-O(7) bond length is 2.09 Å. The V(2)-O(8) bond length is 2.07 Å. Si(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Li(2)O6 octahedra, corners with two equivalent V(1)O6 octahedra, and corners with two equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-47°. The Si(1)-O(2) bond length is 1.66 Å. The Si(1)-O(3) bond length is 1.66 Å. The Si(1)-O(4) bond length is 1.63 Å. The Si(1)-O(5) bond length is 1.63 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(12), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Li(2)O6 octahedra, corners with two equivalent V(1)O6 octahedra, and corners with two equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-46°. The P(1)-O(1) bond length is 1.53 Å. The P(1)-O(12) bond length is 1.54 Å. The P(1)-O(6) bond length is 1.57 Å. The P(1)-O(7) bond length is 1.56 Å. In the second P site, P(2) is bonded to one O(10), one O(11), one O(8), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Li(2)O6 octahedra, corners with two equivalent V(1)O6 octahedra, and corners with two equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-45°. The P(2)-O(10) bond length is 1.57 Å. The P(2)-O(11) bond length is 1.57 Å. The P(2)-O(8) bond length is 1.54 Å. The P(2)-O(9) bond length is 1.53 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(1), one V(2), and one P(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one V(2), and one Si(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Li(1), one Li(2), one Li(3), one V(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Li(3), one V(2), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Li(1), one V(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Li(3), one V(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal pyramidal geometry to one Li(2), one Li(3), one V(2), and one P(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Li(4), one V(2), and one P(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Li(3), one V(1), and one P(2) atom. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Li(3), one Li(4), one V(2), and one P(2) atom. In the eleventh O site, O(11) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Li(4), one V(1), and one P(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Li(4), one V(1), and one P(1) atom.