NaEuP2O7 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(6), two equivalent O(5), and two equivalent O(7) atoms. Eu(1) is bonded in a 8-coordinate geometry to one O(3), one O(5), one O(6), one O(7), two equivalent O(2), and two equivalent O(4) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing PO4 tetrahedra. In the second P site, P(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form corner-sharing PO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1), one Eu(1), and one P(2) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one Eu(1), and one P(2) atom. In the third O site, O(7) is bonded in a 1-coordinate geometry to two equivalent Na(1), one Eu(1), and one P(2) atom. In the fourth O site, O(1) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(2) is bonded in a distorted single-bond geometry to one Na(1), two equivalent Eu(1), and one P(1) atom. In the sixth O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Eu(1), and one P(1) atom. In the seventh O site, O(4) is bonded in a distorted single-bond geometry to one Na(1), two equivalent Eu(1), and one P(1) atom.
NaEuP2O7 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(6), two equivalent O(5), and two equivalent O(7) atoms. The Na(1)-O(2) bond length is 2.61 Å. The Na(1)-O(3) bond length is 2.28 Å. The Na(1)-O(4) bond length is 2.87 Å. The Na(1)-O(6) bond length is 2.62 Å. There is one shorter (2.52 Å) and one longer (2.55 Å) Na(1)-O(5) bond length. There is one shorter (2.46 Å) and one longer (2.98 Å) Na(1)-O(7) bond length. Eu(1) is bonded in a 8-coordinate geometry to one O(3), one O(5), one O(6), one O(7), two equivalent O(2), and two equivalent O(4) atoms. The Eu(1)-O(3) bond length is 2.53 Å. The Eu(1)-O(5) bond length is 2.43 Å. The Eu(1)-O(6) bond length is 2.39 Å. The Eu(1)-O(7) bond length is 2.47 Å. There is one shorter (2.48 Å) and one longer (2.69 Å) Eu(1)-O(2) bond length. There is one shorter (2.58 Å) and one longer (2.60 Å) Eu(1)-O(4) bond length. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing PO4 tetrahedra. The P(1)-O(1) bond length is 1.62 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.52 Å. The P(1)-O(4) bond length is 1.54 Å. In the second P site, P(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form corner-sharing PO4 tetrahedra. The P(2)-O(1) bond length is 1.63 Å. The P(2)-O(5) bond length is 1.54 Å. The P(2)-O(6) bond length is 1.52 Å. The P(2)-O(7) bond length is 1.53 Å. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1), one Eu(1), and one P(2) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one Eu(1), and one P(2) atom. In the third O site, O(7) is bonded in a 1-coordinate geometry to two equivalent Na(1), one Eu(1), and one P(2) atom. In the fourth O site, O(1) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(2) is bonded in a distorted single-bond geometry to one Na(1), two equivalent Eu(1), and one P(1) atom. In the sixth O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Eu(1), and one P(1) atom. In the seventh O site, O(4) is bonded in a distorted single-bond geometry to one Na(1), two equivalent Eu(1), and one P(1) atom.