Na2(TaSe2)3 crystallizes in the trigonal R32 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to three equivalent Se(1) and three equivalent Se(2) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to three equivalent Se(1) and three equivalent Se(2) atoms. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to six equivalent Se(1) atoms to form distorted edge-sharing TaSe6 pentagonal pyramids. In the second Ta site, Ta(2) is bonded to six equivalent Se(1) atoms to form distorted edge-sharing TaSe6 pentagonal pyramids. In the third Ta site, Ta(3) is bonded to six equivalent Se(2) atoms to form distorted edge-sharing TaSe6 pentagonal pyramids. There are two inequivalent Se sites. In the first Se site, Se(2) is bonded to one Na(1), one Na(2), and three equivalent Ta(3) atoms to form a mixture of face, corner, and edge-sharing SeNa2Ta3 square pyramids. In the second Se site, Se(1) is bonded to one Na(1), one Na(2), one Ta(2), and two equivalent Ta(1) atoms to form a mixture of distorted face, corner, and edge-sharing SeNa2Ta3 trigonal bipyramids.
Na2(TaSe2)3 crystallizes in the trigonal R32 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to three equivalent Se(1) and three equivalent Se(2) atoms. All Na(1)-Se(1) bond lengths are 2.96 Å. All Na(1)-Se(2) bond lengths are 2.96 Å. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to three equivalent Se(1) and three equivalent Se(2) atoms. All Na(2)-Se(1) bond lengths are 2.96 Å. All Na(2)-Se(2) bond lengths are 2.96 Å. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to six equivalent Se(1) atoms to form distorted edge-sharing TaSe6 pentagonal pyramids. There are three shorter (2.60 Å) and three longer (2.61 Å) Ta(1)-Se(1) bond lengths. In the second Ta site, Ta(2) is bonded to six equivalent Se(1) atoms to form distorted edge-sharing TaSe6 pentagonal pyramids. All Ta(2)-Se(1) bond lengths are 2.61 Å. In the third Ta site, Ta(3) is bonded to six equivalent Se(2) atoms to form distorted edge-sharing TaSe6 pentagonal pyramids. There are two shorter (2.60 Å) and four longer (2.61 Å) Ta(3)-Se(2) bond lengths. There are two inequivalent Se sites. In the first Se site, Se(2) is bonded to one Na(1), one Na(2), and three equivalent Ta(3) atoms to form a mixture of face, corner, and edge-sharing SeNa2Ta3 square pyramids. In the second Se site, Se(1) is bonded to one Na(1), one Na(2), one Ta(2), and two equivalent Ta(1) atoms to form a mixture of distorted face, corner, and edge-sharing SeNa2Ta3 trigonal bipyramids.