LiFe3SiPO8 crystallizes in the monoclinic Pc space group. Li(1) is bonded in a 3-coordinate geometry to one O(2), one O(4), one O(5), and one O(7) atom. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(8) atom to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Fe(2)O5 trigonal bipyramids,  an edgeedge with one Si(1)O4 tetrahedra, and  an edgeedge with one Fe(2)O5 trigonal bipyramid. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(8) atom to form FeO5 trigonal bipyramids that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Si(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. In the third Fe site, Fe(3) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(5), one O(7), and one O(8) atom. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Fe(1)O5 trigonal bipyramids, corners with two equivalent Fe(2)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O5 trigonal bipyramid, and  an edgeedge with one Fe(2)O5 trigonal bipyramid. P(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O5 trigonal bipyramid and  a cornercorner with one Fe(2)O5 trigonal bipyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Fe(1), one Fe(2), one Fe(3), and one Si(1) atom to form distorted corner-sharing OFe3Si trigonal pyramids. In the second O site, O(2) is bonded to one Li(1), one Fe(1), one Fe(2), and one Si(1) atom to form distorted corner-sharing OLiFe2Si tetrahedra. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(1), one Fe(3), and one P(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Li(1), one Fe(1), one Fe(3), and one P(1) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Fe(2) and one P(1) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(1), one Fe(3), and one P(1) atom. In the eighth O site, O(8) is bonded in a 1-coordinate geometry to one Fe(1), one Fe(2), one Fe(3), and one Si(1) atom.
LiFe3SiPO8 crystallizes in the monoclinic Pc space group. Li(1) is bonded in a 3-coordinate geometry to one O(2), one O(4), one O(5), and one O(7) atom. The Li(1)-O(2) bond length is 1.99 Å. The Li(1)-O(4) bond length is 2.02 Å. The Li(1)-O(5) bond length is 2.62 Å. The Li(1)-O(7) bond length is 2.02 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(8) atom to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Fe(2)O5 trigonal bipyramids,  an edgeedge with one Si(1)O4 tetrahedra, and  an edgeedge with one Fe(2)O5 trigonal bipyramid. The Fe(1)-O(1) bond length is 2.14 Å. The Fe(1)-O(2) bond length is 2.12 Å. The Fe(1)-O(3) bond length is 2.07 Å. The Fe(1)-O(5) bond length is 2.13 Å. The Fe(1)-O(8) bond length is 2.27 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(8) atom to form FeO5 trigonal bipyramids that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Si(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The Fe(2)-O(1) bond length is 2.19 Å. The Fe(2)-O(2) bond length is 2.20 Å. The Fe(2)-O(3) bond length is 2.04 Å. The Fe(2)-O(6) bond length is 1.97 Å. The Fe(2)-O(8) bond length is 2.19 Å. In the third Fe site, Fe(3) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(5), one O(7), and one O(8) atom. The Fe(3)-O(1) bond length is 2.18 Å. The Fe(3)-O(4) bond length is 1.99 Å. The Fe(3)-O(5) bond length is 2.11 Å. The Fe(3)-O(7) bond length is 2.08 Å. The Fe(3)-O(8) bond length is 2.62 Å. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Fe(1)O5 trigonal bipyramids, corners with two equivalent Fe(2)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O5 trigonal bipyramid, and  an edgeedge with one Fe(2)O5 trigonal bipyramid. The Si(1)-O(1) bond length is 1.68 Å. The Si(1)-O(2) bond length is 1.68 Å. The Si(1)-O(3) bond length is 1.64 Å. The Si(1)-O(8) bond length is 1.67 Å. P(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O5 trigonal bipyramid and  a cornercorner with one Fe(2)O5 trigonal bipyramid. The P(1)-O(4) bond length is 1.55 Å. The P(1)-O(5) bond length is 1.59 Å. The P(1)-O(6) bond length is 1.52 Å. The P(1)-O(7) bond length is 1.56 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Fe(1), one Fe(2), one Fe(3), and one Si(1) atom to form distorted corner-sharing OFe3Si trigonal pyramids. In the second O site, O(2) is bonded to one Li(1), one Fe(1), one Fe(2), and one Si(1) atom to form distorted corner-sharing OLiFe2Si tetrahedra. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(1), one Fe(3), and one P(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Li(1), one Fe(1), one Fe(3), and one P(1) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Fe(2) and one P(1) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(1), one Fe(3), and one P(1) atom. In the eighth O site, O(8) is bonded in a 1-coordinate geometry to one Fe(1), one Fe(2), one Fe(3), and one Si(1) atom.