Na2LiFeCPO7 crystallizes in the monoclinic Pc space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(12), one O(13), one O(4), one O(5), and two equivalent O(1) atoms. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(14), one O(8), and one O(9) atom. In the fourth Na site, Na(4) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(14), one O(8), and one O(9) atom. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), one O(4), one O(6), and one O(7) atom to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 64-88°. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(10), one O(11), one O(14), one O(2), and one O(3) atom. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(7), and one O(9) atom to form distorted FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  a cornercorner with one Li(1)O5 trigonal bipyramid, and  an edgeedge with one Li(1)O5 trigonal bipyramid. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(12), one O(13), one O(6), and one O(8) atom to form distorted FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  a cornercorner with one Li(1)O5 trigonal bipyramid. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(14), one O(2), and one O(3) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(1), one O(12), and one O(13) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with two equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 43-59°. In the second P site, P(2) is bonded to one O(10), one O(11), one O(7), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and  a cornercorner with one Li(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-56°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(1), one Li(1), and one C(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Na(2), one Li(2), one Fe(1), and one C(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one Na(2), one Li(1), one Li(2), one Fe(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Li(1), one Fe(1), and one P(1) atom. In the fifth O site, O(5) is bonded to one Na(1), one Na(2), one Fe(1), and one P(1) atom to form distorted ONa2FeP trigonal pyramids that share corners with two equivalent O(6)NaLiFeP tetrahedra and  a cornercorner with one O(12)Na3FeC trigonal bipyramid. In the sixth O site, O(6) is bonded to one Na(2), one Li(1), one Fe(2), and one P(1) atom to form distorted ONaLiFeP tetrahedra that share  a cornercorner with one O(12)Na3FeC trigonal bipyramid and corners with two equivalent O(5)Na2FeP trigonal pyramids. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), one Li(1), one Fe(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Na(3), one Na(4), one Fe(2), and one P(1) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Na(3), one Na(4), one Fe(1), and one P(2) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Na(3), one Na(4), one Li(2), one Fe(2), and one P(2) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Na(3), one Na(4), one Li(2), one Fe(2), and one P(2) atom. In the twelfth O site, O(12) is bonded to one Na(1), one Na(3), one Na(4), one Fe(2), and one C(2) atom to form distorted ONa3FeC trigonal bipyramids that share  a cornercorner with one O(6)NaLiFeP tetrahedra, corners with two equivalent O(14)Na2LiC tetrahedra, and  a cornercorner with one O(5)Na2FeP trigonal pyramid. In the thirteenth O site, O(13) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Na(4), one Fe(2), and one C(2) atom. In the fourteenth O site, O(14) is bonded to one Na(3), one Na(4), one Li(2), and one C(1) atom to form distorted corner-sharing ONa2LiC tetrahedra.
Na2LiFeCPO7 crystallizes in the monoclinic Pc space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(12), one O(13), one O(4), one O(5), and two equivalent O(1) atoms. The Na(1)-O(12) bond length is 2.46 Å. The Na(1)-O(13) bond length is 2.30 Å. The Na(1)-O(4) bond length is 2.41 Å. The Na(1)-O(5) bond length is 2.44 Å. There is one shorter (2.48 Å) and one longer (2.68 Å) Na(1)-O(1) bond length. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. The Na(2)-O(1) bond length is 2.39 Å. The Na(2)-O(2) bond length is 2.70 Å. The Na(2)-O(3) bond length is 2.40 Å. The Na(2)-O(4) bond length is 2.84 Å. The Na(2)-O(5) bond length is 2.42 Å. The Na(2)-O(6) bond length is 2.45 Å. The Na(2)-O(7) bond length is 2.39 Å. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(14), one O(8), and one O(9) atom. The Na(3)-O(10) bond length is 2.76 Å. The Na(3)-O(11) bond length is 2.48 Å. The Na(3)-O(12) bond length is 2.42 Å. The Na(3)-O(13) bond length is 2.61 Å. The Na(3)-O(14) bond length is 2.29 Å. The Na(3)-O(8) bond length is 2.30 Å. The Na(3)-O(9) bond length is 2.41 Å. In the fourth Na site, Na(4) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(14), one O(8), and one O(9) atom. The Na(4)-O(10) bond length is 2.51 Å. The Na(4)-O(11) bond length is 2.85 Å. The Na(4)-O(12) bond length is 2.40 Å. The Na(4)-O(13) bond length is 2.62 Å. The Na(4)-O(14) bond length is 2.30 Å. The Na(4)-O(8) bond length is 2.30 Å. The Na(4)-O(9) bond length is 2.42 Å. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), one O(4), one O(6), and one O(7) atom to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 64-88°. The Li(1)-O(1) bond length is 2.16 Å. The Li(1)-O(3) bond length is 2.46 Å. The Li(1)-O(4) bond length is 2.41 Å. The Li(1)-O(6) bond length is 2.22 Å. The Li(1)-O(7) bond length is 2.16 Å. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(10), one O(11), one O(14), one O(2), and one O(3) atom. The Li(2)-O(10) bond length is 2.32 Å. The Li(2)-O(11) bond length is 2.47 Å. The Li(2)-O(14) bond length is 2.12 Å. The Li(2)-O(2) bond length is 2.15 Å. The Li(2)-O(3) bond length is 2.61 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(7), and one O(9) atom to form distorted FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  a cornercorner with one Li(1)O5 trigonal bipyramid, and  an edgeedge with one Li(1)O5 trigonal bipyramid. The Fe(1)-O(2) bond length is 2.42 Å. The Fe(1)-O(3) bond length is 2.19 Å. The Fe(1)-O(4) bond length is 2.10 Å. The Fe(1)-O(5) bond length is 2.07 Å. The Fe(1)-O(7) bond length is 2.15 Å. The Fe(1)-O(9) bond length is 2.10 Å. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(12), one O(13), one O(6), and one O(8) atom to form distorted FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  a cornercorner with one Li(1)O5 trigonal bipyramid. The Fe(2)-O(10) bond length is 2.11 Å. The Fe(2)-O(11) bond length is 2.10 Å. The Fe(2)-O(12) bond length is 2.37 Å. The Fe(2)-O(13) bond length is 2.23 Å. The Fe(2)-O(6) bond length is 2.14 Å. The Fe(2)-O(8) bond length is 2.14 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(14), one O(2), and one O(3) atom. The C(1)-O(14) bond length is 1.29 Å. The C(1)-O(2) bond length is 1.30 Å. The C(1)-O(3) bond length is 1.31 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(1), one O(12), and one O(13) atom. The C(2)-O(1) bond length is 1.29 Å. The C(2)-O(12) bond length is 1.31 Å. The C(2)-O(13) bond length is 1.30 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with two equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 43-59°. The P(1)-O(4) bond length is 1.56 Å. The P(1)-O(5) bond length is 1.56 Å. The P(1)-O(6) bond length is 1.57 Å. The P(1)-O(8) bond length is 1.54 Å. In the second P site, P(2) is bonded to one O(10), one O(11), one O(7), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and  a cornercorner with one Li(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-56°. The P(2)-O(10) bond length is 1.57 Å. The P(2)-O(11) bond length is 1.56 Å. The P(2)-O(7) bond length is 1.55 Å. The P(2)-O(9) bond length is 1.56 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(1), one Li(1), and one C(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Na(2), one Li(2), one Fe(1), and one C(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one Na(2), one Li(1), one Li(2), one Fe(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Li(1), one Fe(1), and one P(1) atom. In the fifth O site, O(5) is bonded to one Na(1), one Na(2), one Fe(1), and one P(1) atom to form distorted ONa2FeP trigonal pyramids that share corners with two equivalent O(6)NaLiFeP tetrahedra and  a cornercorner with one O(12)Na3FeC trigonal bipyramid. In the sixth O site, O(6) is bonded to one Na(2), one Li(1), one Fe(2), and one P(1) atom to form distorted ONaLiFeP tetrahedra that share  a cornercorner with one O(12)Na3FeC trigonal bipyramid and corners with two equivalent O(5)Na2FeP trigonal pyramids. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), one Li(1), one Fe(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Na(3), one Na(4), one Fe(2), and one P(1) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Na(3), one Na(4), one Fe(1), and one P(2) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Na(3), one Na(4), one Li(2), one Fe(2), and one P(2) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Na(3), one Na(4), one Li(2), one Fe(2), and one P(2) atom. In the twelfth O site, O(12) is bonded to one Na(1), one Na(3), one Na(4), one Fe(2), and one C(2) atom to form distorted ONa3FeC trigonal bipyramids that share  a cornercorner with one O(6)NaLiFeP tetrahedra, corners with two equivalent O(14)Na2LiC tetrahedra, and  a cornercorner with one O(5)Na2FeP trigonal pyramid. In the thirteenth O site, O(13) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Na(4), one Fe(2), and one C(2) atom. In the fourteenth O site, O(14) is bonded to one Na(3), one Na(4), one Li(2), and one C(1) atom to form distorted corner-sharing ONa2LiC tetrahedra.