Ti16Hg4C5 crystallizes in the tetragonal P4/mmm space group. There are seven inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one Ti(7), one Hg(1), and four equivalent C(1) atoms. In the second Ti site, Ti(2) is bonded in a 5-coordinate geometry to one Hg(1) and four equivalent C(2) atoms. In the third Ti site, Ti(3) is bonded to eight equivalent Ti(6) and four equivalent C(3) atoms to form distorted TiTi8C4 cuboctahedra that share corners with four equivalent Ti(3)Ti8C4 cuboctahedra, faces with four equivalent Ti(3)Ti8C4 cuboctahedra, and faces with four equivalent C(3)Ti12 cuboctahedra. In the fourth Ti site, Ti(4) is bonded to two equivalent Ti(7) and four equivalent C(1) atoms to form a mixture of face, corner, and edge-sharing TiTi2C4 octahedra. The corner-sharing octahedra are not tilted. In the fifth Ti site, Ti(5) is bonded in a bent 120 degrees geometry to two equivalent Hg(2) and two equivalent C(2) atoms. In the sixth Ti site, Ti(6) is bonded in a 10-coordinate geometry to two equivalent Ti(3), four equivalent Ti(6), two equivalent Hg(2), and two equivalent C(3) atoms. In the seventh Ti site, Ti(7) is bonded to two equivalent Ti(1) and four equivalent Ti(4) atoms to form corner-sharing TiTi6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a linear geometry to one Ti(1) and one Ti(2) atom. In the second Hg site, Hg(2) is bonded in a 8-coordinate geometry to four equivalent Ti(5) and four equivalent Ti(6) atoms. There are three inequivalent C sites. In the first C site, C(1) is bonded in a 8-coordinate geometry to four equivalent Ti(1) and four equivalent Ti(4) atoms. In the second C site, C(2) is bonded in a 8-coordinate geometry to four equivalent Ti(2) and four equivalent Ti(5) atoms. In the third C site, C(3) is bonded to four equivalent Ti(3) and eight equivalent Ti(6) atoms to form CTi12 cuboctahedra that share corners with four equivalent C(3)Ti12 cuboctahedra, faces with four equivalent Ti(3)Ti8C4 cuboctahedra, and faces with four equivalent C(3)Ti12 cuboctahedra.
Ti16Hg4C5 crystallizes in the tetragonal P4/mmm space group. There are seven inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one Ti(7), one Hg(1), and four equivalent C(1) atoms. The Ti(1)-Ti(7) bond length is 2.43 Å. The Ti(1)-Hg(1) bond length is 2.85 Å. All Ti(1)-C(1) bond lengths are 2.78 Å. In the second Ti site, Ti(2) is bonded in a 5-coordinate geometry to one Hg(1) and four equivalent C(2) atoms. The Ti(2)-Hg(1) bond length is 2.89 Å. All Ti(2)-C(2) bond lengths are 2.78 Å. In the third Ti site, Ti(3) is bonded to eight equivalent Ti(6) and four equivalent C(3) atoms to form distorted TiTi8C4 cuboctahedra that share corners with four equivalent Ti(3)Ti8C4 cuboctahedra, faces with four equivalent Ti(3)Ti8C4 cuboctahedra, and faces with four equivalent C(3)Ti12 cuboctahedra. All Ti(3)-Ti(6) bond lengths are 2.58 Å. All Ti(3)-C(3) bond lengths are 2.66 Å. In the fourth Ti site, Ti(4) is bonded to two equivalent Ti(7) and four equivalent C(1) atoms to form a mixture of face, corner, and edge-sharing TiTi2C4 octahedra. The corner-sharing octahedra are not tilted. Both Ti(4)-Ti(7) bond lengths are 1.88 Å. All Ti(4)-C(1) bond lengths are 2.50 Å. In the fifth Ti site, Ti(5) is bonded in a bent 120 degrees geometry to two equivalent Hg(2) and two equivalent C(2) atoms. Both Ti(5)-Hg(2) bond lengths are 3.08 Å. Both Ti(5)-C(2) bond lengths are 2.19 Å. In the sixth Ti site, Ti(6) is bonded in a 10-coordinate geometry to two equivalent Ti(3), four equivalent Ti(6), two equivalent Hg(2), and two equivalent C(3) atoms. All Ti(6)-Ti(6) bond lengths are 2.66 Å. Both Ti(6)-Hg(2) bond lengths are 3.07 Å. Both Ti(6)-C(3) bond lengths are 2.58 Å. In the seventh Ti site, Ti(7) is bonded to two equivalent Ti(1) and four equivalent Ti(4) atoms to form corner-sharing TiTi6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a linear geometry to one Ti(1) and one Ti(2) atom. In the second Hg site, Hg(2) is bonded in a 8-coordinate geometry to four equivalent Ti(5) and four equivalent Ti(6) atoms. There are three inequivalent C sites. In the first C site, C(1) is bonded in a 8-coordinate geometry to four equivalent Ti(1) and four equivalent Ti(4) atoms. In the second C site, C(2) is bonded in a 8-coordinate geometry to four equivalent Ti(2) and four equivalent Ti(5) atoms. In the third C site, C(3) is bonded to four equivalent Ti(3) and eight equivalent Ti(6) atoms to form CTi12 cuboctahedra that share corners with four equivalent C(3)Ti12 cuboctahedra, faces with four equivalent Ti(3)Ti8C4 cuboctahedra, and faces with four equivalent C(3)Ti12 cuboctahedra.