Na2PtSe2 is Magnesium tetraboride-derived structured and crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to two equivalent Pt(1), two equivalent Se(1), and three equivalent Se(2) atoms. In the second Na site, Na(2) is bonded in a 8-coordinate geometry to two equivalent Pt(1), three equivalent Se(1), and three equivalent Se(2) atoms. Pt(1) is bonded in a 8-coordinate geometry to two equivalent Na(1), two equivalent Na(2), two equivalent Se(1), and two equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Na(1), three equivalent Na(2), and two equivalent Pt(1) atoms to form a mixture of distorted corner and edge-sharing SeNa5Pt2 pentagonal bipyramids. In the second Se site, Se(2) is bonded in a 8-coordinate geometry to three equivalent Na(1), three equivalent Na(2), and two equivalent Pt(1) atoms.
Na2PtSe2 is Magnesium tetraboride-derived structured and crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to two equivalent Pt(1), two equivalent Se(1), and three equivalent Se(2) atoms. Both Na(1)-Pt(1) bond lengths are 3.12 Å. Both Na(1)-Se(1) bond lengths are 2.96 Å. There are two shorter (2.96 Å) and one longer (3.05 Å) Na(1)-Se(2) bond length. In the second Na site, Na(2) is bonded in a 8-coordinate geometry to two equivalent Pt(1), three equivalent Se(1), and three equivalent Se(2) atoms. Both Na(2)-Pt(1) bond lengths are 3.24 Å. There is one shorter (2.96 Å) and two longer (3.07 Å) Na(2)-Se(1) bond lengths. There are two shorter (3.19 Å) and one longer (3.29 Å) Na(2)-Se(2) bond length. Pt(1) is bonded in a 8-coordinate geometry to two equivalent Na(1), two equivalent Na(2), two equivalent Se(1), and two equivalent Se(2) atoms. Both Pt(1)-Se(1) bond lengths are 2.48 Å. Both Pt(1)-Se(2) bond lengths are 2.48 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Na(1), three equivalent Na(2), and two equivalent Pt(1) atoms to form a mixture of distorted corner and edge-sharing SeNa5Pt2 pentagonal bipyramids. In the second Se site, Se(2) is bonded in a 8-coordinate geometry to three equivalent Na(1), three equivalent Na(2), and two equivalent Pt(1) atoms.