NaNpO2CO3 crystallizes in the orthorhombic Pmn2_1 space group. Na(1) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(2), and two equivalent O(3) atoms. Np(1) is bonded in a distorted linear geometry to one O(2), one O(3), and two equivalent O(4) atoms. C(1) is bonded in a trigonal planar geometry to one O(4) and two equivalent O(1) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one C(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one Np(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Na(1) and one Np(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Na(1), two equivalent Np(1), and one C(1) atom.
NaNpO2CO3 crystallizes in the orthorhombic Pmn2_1 space group. Na(1) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(2), and two equivalent O(3) atoms. The Na(1)-O(4) bond length is 2.53 Å. Both Na(1)-O(2) bond lengths are 2.61 Å. There is one shorter (2.35 Å) and one longer (2.44 Å) Na(1)-O(3) bond length. Np(1) is bonded in a distorted linear geometry to one O(2), one O(3), and two equivalent O(4) atoms. The Np(1)-O(2) bond length is 1.85 Å. The Np(1)-O(3) bond length is 1.86 Å. Both Np(1)-O(4) bond lengths are 2.50 Å. C(1) is bonded in a trigonal planar geometry to one O(4) and two equivalent O(1) atoms. The C(1)-O(4) bond length is 1.32 Å. Both C(1)-O(1) bond lengths are 1.28 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one C(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one Np(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Na(1) and one Np(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Na(1), two equivalent Np(1), and one C(1) atom.