LiFeP2O7 crystallizes in the monoclinic Cc space group. Li(1) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent P(1)O4 tetrahedra. Fe(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(3), one O(4), and one O(7) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Li(1)O4 tetrahedra. In the second P site, P(2) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra and  a cornercorner with one P(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Li(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Li(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom.
LiFeP2O7 crystallizes in the monoclinic Cc space group. Li(1) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent P(1)O4 tetrahedra. The Li(1)-O(3) bond length is 2.23 Å. The Li(1)-O(5) bond length is 1.93 Å. The Li(1)-O(6) bond length is 1.87 Å. The Li(1)-O(7) bond length is 2.15 Å. Fe(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(3), one O(4), and one O(7) atom. The Fe(1)-O(1) bond length is 1.90 Å. The Fe(1)-O(3) bond length is 1.97 Å. The Fe(1)-O(4) bond length is 1.88 Å. The Fe(1)-O(7) bond length is 1.97 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Li(1)O4 tetrahedra. The P(1)-O(2) bond length is 1.66 Å. The P(1)-O(3) bond length is 1.54 Å. The P(1)-O(5) bond length is 1.48 Å. The P(1)-O(7) bond length is 1.56 Å. In the second P site, P(2) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra and  a cornercorner with one P(1)O4 tetrahedra. The P(2)-O(1) bond length is 1.53 Å. The P(2)-O(2) bond length is 1.66 Å. The P(2)-O(4) bond length is 1.54 Å. The P(2)-O(6) bond length is 1.49 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Li(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Li(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom.