BaNpPH2O7 crystallizes in the monoclinic P2_1/c space group. Ba(1) is bonded in a 8-coordinate geometry to one O(2), one O(7), two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms. Np(1) is bonded to one O(4), one O(5), one O(6), two equivalent O(1), and two equivalent O(2) atoms to form distorted NpO7 pentagonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra, edges with two equivalent Np(1)O7 pentagonal bipyramids, and  an edgeedge with one P(1)O4 tetrahedra. P(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form PO4 tetrahedra that share corners with three equivalent Np(1)O7 pentagonal bipyramids and  an edgeedge with one Np(1)O7 pentagonal bipyramid. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(7) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(7) atom. There are seven inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one Np(1) atom. In the second O site, O(5) is bonded in a 2-coordinate geometry to one Np(1) and one P(1) atom. In the third O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one Np(1) atom. In the fourth O site, O(7) is bonded in a water-like geometry to one Ba(1), one H(1), and one H(2) atom. In the fifth O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Np(1) and one P(1) atom. In the sixth O site, O(2) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Np(1), and one P(1) atom. In the seventh O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one P(1) atom.
BaNpPH2O7 crystallizes in the monoclinic P2_1/c space group. Ba(1) is bonded in a 8-coordinate geometry to one O(2), one O(7), two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms. The Ba(1)-O(2) bond length is 2.87 Å. The Ba(1)-O(7) bond length is 2.77 Å. There is one shorter (2.78 Å) and one longer (2.82 Å) Ba(1)-O(3) bond length. There is one shorter (2.91 Å) and one longer (2.93 Å) Ba(1)-O(4) bond length. There is one shorter (2.77 Å) and one longer (3.17 Å) Ba(1)-O(6) bond length. Np(1) is bonded to one O(4), one O(5), one O(6), two equivalent O(1), and two equivalent O(2) atoms to form distorted NpO7 pentagonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra, edges with two equivalent Np(1)O7 pentagonal bipyramids, and  an edgeedge with one P(1)O4 tetrahedra. The Np(1)-O(4) bond length is 1.90 Å. The Np(1)-O(5) bond length is 2.33 Å. The Np(1)-O(6) bond length is 1.88 Å. There is one shorter (2.43 Å) and one longer (2.57 Å) Np(1)-O(1) bond length. There is one shorter (2.42 Å) and one longer (2.46 Å) Np(1)-O(2) bond length. P(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form PO4 tetrahedra that share corners with three equivalent Np(1)O7 pentagonal bipyramids and  an edgeedge with one Np(1)O7 pentagonal bipyramid. The P(1)-O(1) bond length is 1.57 Å. The P(1)-O(2) bond length is 1.60 Å. The P(1)-O(3) bond length is 1.53 Å. The P(1)-O(5) bond length is 1.55 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(7) atom. The H(1)-O(7) bond length is 0.99 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(7) atom. The H(2)-O(7) bond length is 0.97 Å. There are seven inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one Np(1) atom. In the second O site, O(5) is bonded in a 2-coordinate geometry to one Np(1) and one P(1) atom. In the third O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one Np(1) atom. In the fourth O site, O(7) is bonded in a water-like geometry to one Ba(1), one H(1), and one H(2) atom. In the fifth O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Np(1) and one P(1) atom. In the sixth O site, O(2) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Np(1), and one P(1) atom. In the seventh O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one P(1) atom.