Na2Ti3Cl8 crystallizes in the trigonal R3m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to three equivalent Cl(1) and three equivalent Cl(2) atoms to form distorted NaCl6 pentagonal pyramids that share corners with six equivalent Ti(1)Cl6 octahedra, edges with three equivalent Ti(1)Cl6 octahedra, and edges with three equivalent Na(2)Cl6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 37°. In the second Na site, Na(2) is bonded to three equivalent Cl(1) and three equivalent Cl(2) atoms to form distorted NaCl6 pentagonal pyramids that share corners with six equivalent Ti(1)Cl6 octahedra, edges with three equivalent Ti(1)Cl6 octahedra, and edges with three equivalent Na(1)Cl6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 54°. Ti(1) is bonded to one Cl(3), one Cl(4), two equivalent Cl(1), and two equivalent Cl(2) atoms to form distorted TiCl6 octahedra that share corners with two equivalent Na(1)Cl6 pentagonal pyramids, corners with two equivalent Na(2)Cl6 pentagonal pyramids, edges with four equivalent Ti(1)Cl6 octahedra,  an edgeedge with one Na(1)Cl6 pentagonal pyramid, and  an edgeedge with one Na(2)Cl6 pentagonal pyramid. There are four inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to one Na(1), one Na(2), and two equivalent Ti(1) atoms to form a mixture of corner and edge-sharing ClNa2Ti2 trigonal pyramids. In the second Cl site, Cl(2) is bonded in a rectangular see-saw-like geometry to one Na(1), one Na(2), and two equivalent Ti(1) atoms. In the third Cl site, Cl(3) is bonded in a 3-coordinate geometry to three equivalent Ti(1) atoms. In the fourth Cl site, Cl(4) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Ti(1) atoms.
Na2Ti3Cl8 crystallizes in the trigonal R3m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to three equivalent Cl(1) and three equivalent Cl(2) atoms to form distorted NaCl6 pentagonal pyramids that share corners with six equivalent Ti(1)Cl6 octahedra, edges with three equivalent Ti(1)Cl6 octahedra, and edges with three equivalent Na(2)Cl6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 37°. All Na(1)-Cl(1) bond lengths are 2.74 Å. All Na(1)-Cl(2) bond lengths are 2.80 Å. In the second Na site, Na(2) is bonded to three equivalent Cl(1) and three equivalent Cl(2) atoms to form distorted NaCl6 pentagonal pyramids that share corners with six equivalent Ti(1)Cl6 octahedra, edges with three equivalent Ti(1)Cl6 octahedra, and edges with three equivalent Na(1)Cl6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 54°. All Na(2)-Cl(1) bond lengths are 2.72 Å. All Na(2)-Cl(2) bond lengths are 2.81 Å. Ti(1) is bonded to one Cl(3), one Cl(4), two equivalent Cl(1), and two equivalent Cl(2) atoms to form distorted TiCl6 octahedra that share corners with two equivalent Na(1)Cl6 pentagonal pyramids, corners with two equivalent Na(2)Cl6 pentagonal pyramids, edges with four equivalent Ti(1)Cl6 octahedra,  an edgeedge with one Na(1)Cl6 pentagonal pyramid, and  an edgeedge with one Na(2)Cl6 pentagonal pyramid. The Ti(1)-Cl(3) bond length is 2.40 Å. The Ti(1)-Cl(4) bond length is 2.67 Å. Both Ti(1)-Cl(1) bond lengths are 2.58 Å. Both Ti(1)-Cl(2) bond lengths are 2.41 Å. There are four inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to one Na(1), one Na(2), and two equivalent Ti(1) atoms to form a mixture of corner and edge-sharing ClNa2Ti2 trigonal pyramids. In the second Cl site, Cl(2) is bonded in a rectangular see-saw-like geometry to one Na(1), one Na(2), and two equivalent Ti(1) atoms. In the third Cl site, Cl(3) is bonded in a 3-coordinate geometry to three equivalent Ti(1) atoms. In the fourth Cl site, Cl(4) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Ti(1) atoms.