Ti3Cr9Si4 crystallizes in the monoclinic Pm space group. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 14-coordinate geometry to one Cr(4), one Cr(5), two equivalent Cr(1), two equivalent Cr(7), four equivalent Cr(2), two equivalent Si(1), and two equivalent Si(4) atoms. In the second Ti site, Ti(2) is bonded in a 6-coordinate geometry to one Cr(4), one Cr(5), four equivalent Cr(3), two equivalent Si(2), and two equivalent Si(3) atoms. In the third Ti site, Ti(3) is bonded in a 6-coordinate geometry to two equivalent Cr(2), two equivalent Cr(3), two equivalent Cr(6), one Si(1), one Si(2), and two equivalent Si(3) atoms. There are seven inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 14-coordinate geometry to two equivalent Ti(1), two equivalent Cr(2), two equivalent Cr(3), two equivalent Cr(5), two equivalent Cr(7), one Si(1), one Si(2), and two equivalent Si(4) atoms. In the second Cr site, Cr(2) is bonded in a 14-coordinate geometry to one Ti(3), two equivalent Ti(1), one Cr(1), one Cr(6), one Cr(7), two equivalent Cr(2), two equivalent Cr(4), one Si(3), one Si(4), and two equivalent Si(1) atoms. In the third Cr site, Cr(3) is bonded in a 14-coordinate geometry to one Ti(3), two equivalent Ti(2), one Cr(1), one Cr(6), one Cr(7), two equivalent Cr(3), two equivalent Cr(5), one Si(3), one Si(4), and two equivalent Si(2) atoms. In the fourth Cr site, Cr(4) is bonded in a 6-coordinate geometry to one Ti(1), one Ti(2), four equivalent Cr(2), two equivalent Si(1), and two equivalent Si(3) atoms. In the fifth Cr site, Cr(5) is bonded in a 6-coordinate geometry to one Ti(1), one Ti(2), two equivalent Cr(1), two equivalent Cr(7), four equivalent Cr(3), two equivalent Si(2), and two equivalent Si(4) atoms. In the sixth Cr site, Cr(6) is bonded in a 6-coordinate geometry to two equivalent Ti(3), two equivalent Cr(2), two equivalent Cr(3), one Si(1), one Si(2), and two equivalent Si(3) atoms. In the seventh Cr site, Cr(7) is bonded in a 14-coordinate geometry to two equivalent Ti(1), two equivalent Cr(1), two equivalent Cr(2), two equivalent Cr(3), two equivalent Cr(5), one Si(1), one Si(2), and two equivalent Si(4) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one Ti(3), two equivalent Ti(1), one Cr(1), one Cr(6), one Cr(7), two equivalent Cr(4), and four equivalent Cr(2) atoms to form SiTi3Cr9 cuboctahedra that share edges with two equivalent Si(2)Ti3Cr9 cuboctahedra, edges with four equivalent Si(1)Ti3Cr9 cuboctahedra, faces with four equivalent Si(4)Ti2Cr10 cuboctahedra, and faces with four equivalent Si(3)Ti4Cr8 cuboctahedra. In the second Si site, Si(2) is bonded to one Ti(3), two equivalent Ti(2), one Cr(1), one Cr(6), one Cr(7), two equivalent Cr(5), and four equivalent Cr(3) atoms to form SiTi3Cr9 cuboctahedra that share edges with two equivalent Si(1)Ti3Cr9 cuboctahedra, edges with four equivalent Si(2)Ti3Cr9 cuboctahedra, faces with four equivalent Si(4)Ti2Cr10 cuboctahedra, and faces with four equivalent Si(3)Ti4Cr8 cuboctahedra. In the third Si site, Si(3) is bonded to two equivalent Ti(2), two equivalent Ti(3), two equivalent Cr(2), two equivalent Cr(3), two equivalent Cr(4), and two equivalent Cr(6) atoms to form SiTi4Cr8 cuboctahedra that share edges with two equivalent Si(4)Ti2Cr10 cuboctahedra, edges with four equivalent Si(3)Ti4Cr8 cuboctahedra, faces with four equivalent Si(1)Ti3Cr9 cuboctahedra, and faces with four equivalent Si(2)Ti3Cr9 cuboctahedra. In the fourth Si site, Si(4) is bonded to two equivalent Ti(1), two equivalent Cr(1), two equivalent Cr(2), two equivalent Cr(3), two equivalent Cr(5), and two equivalent Cr(7) atoms to form SiTi2Cr10 cuboctahedra that share edges with two equivalent Si(3)Ti4Cr8 cuboctahedra, edges with four equivalent Si(4)Ti2Cr10 cuboctahedra, faces with four equivalent Si(1)Ti3Cr9 cuboctahedra, and faces with four equivalent Si(2)Ti3Cr9 cuboctahedra.
Ti3Cr9Si4 crystallizes in the monoclinic Pm space group. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 14-coordinate geometry to one Cr(4), one Cr(5), two equivalent Cr(1), two equivalent Cr(7), four equivalent Cr(2), two equivalent Si(1), and two equivalent Si(4) atoms. The Ti(1)-Cr(4) bond length is 2.30 Å. The Ti(1)-Cr(5) bond length is 2.27 Å. Both Ti(1)-Cr(1) bond lengths are 2.84 Å. Both Ti(1)-Cr(7) bond lengths are 2.84 Å. There are two shorter (2.83 Å) and two longer (2.84 Å) Ti(1)-Cr(2) bond lengths. Both Ti(1)-Si(1) bond lengths are 2.59 Å. There is one shorter (2.58 Å) and one longer (2.59 Å) Ti(1)-Si(4) bond length. In the second Ti site, Ti(2) is bonded in a 6-coordinate geometry to one Cr(4), one Cr(5), four equivalent Cr(3), two equivalent Si(2), and two equivalent Si(3) atoms. The Ti(2)-Cr(4) bond length is 2.34 Å. The Ti(2)-Cr(5) bond length is 2.29 Å. There are two shorter (2.82 Å) and two longer (2.85 Å) Ti(2)-Cr(3) bond lengths. Both Ti(2)-Si(2) bond lengths are 2.60 Å. There is one shorter (2.58 Å) and one longer (2.63 Å) Ti(2)-Si(3) bond length. In the third Ti site, Ti(3) is bonded in a 6-coordinate geometry to two equivalent Cr(2), two equivalent Cr(3), two equivalent Cr(6), one Si(1), one Si(2), and two equivalent Si(3) atoms. Both Ti(3)-Cr(2) bond lengths are 2.82 Å. Both Ti(3)-Cr(3) bond lengths are 2.85 Å. There is one shorter (2.29 Å) and one longer (2.33 Å) Ti(3)-Cr(6) bond length. The Ti(3)-Si(1) bond length is 2.59 Å. The Ti(3)-Si(2) bond length is 2.63 Å. Both Ti(3)-Si(3) bond lengths are 2.59 Å. There are seven inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 14-coordinate geometry to two equivalent Ti(1), two equivalent Cr(2), two equivalent Cr(3), two equivalent Cr(5), two equivalent Cr(7), one Si(1), one Si(2), and two equivalent Si(4) atoms. Both Cr(1)-Cr(2) bond lengths are 2.79 Å. Both Cr(1)-Cr(3) bond lengths are 2.78 Å. Both Cr(1)-Cr(5) bond lengths are 2.84 Å. There is one shorter (2.26 Å) and one longer (2.36 Å) Cr(1)-Cr(7) bond length. The Cr(1)-Si(1) bond length is 2.58 Å. The Cr(1)-Si(2) bond length is 2.54 Å. Both Cr(1)-Si(4) bond lengths are 2.58 Å. In the second Cr site, Cr(2) is bonded in a 14-coordinate geometry to one Ti(3), two equivalent Ti(1), one Cr(1), one Cr(6), one Cr(7), two equivalent Cr(2), two equivalent Cr(4), one Si(3), one Si(4), and two equivalent Si(1) atoms. The Cr(2)-Cr(6) bond length is 2.82 Å. The Cr(2)-Cr(7) bond length is 2.79 Å. There is one shorter (2.29 Å) and one longer (2.35 Å) Cr(2)-Cr(2) bond length. There is one shorter (2.83 Å) and one longer (2.85 Å) Cr(2)-Cr(4) bond length. The Cr(2)-Si(3) bond length is 2.58 Å. The Cr(2)-Si(4) bond length is 2.58 Å. There is one shorter (2.56 Å) and one longer (2.59 Å) Cr(2)-Si(1) bond length. In the third Cr site, Cr(3) is bonded in a 14-coordinate geometry to one Ti(3), two equivalent Ti(2), one Cr(1), one Cr(6), one Cr(7), two equivalent Cr(3), two equivalent Cr(5), one Si(3), one Si(4), and two equivalent Si(2) atoms. The Cr(3)-Cr(6) bond length is 2.84 Å. The Cr(3)-Cr(7) bond length is 2.78 Å. There is one shorter (2.29 Å) and one longer (2.35 Å) Cr(3)-Cr(3) bond length. Both Cr(3)-Cr(5) bond lengths are 2.83 Å. The Cr(3)-Si(3) bond length is 2.63 Å. The Cr(3)-Si(4) bond length is 2.54 Å. There is one shorter (2.57 Å) and one longer (2.59 Å) Cr(3)-Si(2) bond length. In the fourth Cr site, Cr(4) is bonded in a 6-coordinate geometry to one Ti(1), one Ti(2), four equivalent Cr(2), two equivalent Si(1), and two equivalent Si(3) atoms. Both Cr(4)-Si(1) bond lengths are 2.59 Å. There is one shorter (2.56 Å) and one longer (2.60 Å) Cr(4)-Si(3) bond length. In the fifth Cr site, Cr(5) is bonded in a 6-coordinate geometry to one Ti(1), one Ti(2), two equivalent Cr(1), two equivalent Cr(7), four equivalent Cr(3), two equivalent Si(2), and two equivalent Si(4) atoms. Both Cr(5)-Cr(7) bond lengths are 2.84 Å. Both Cr(5)-Si(2) bond lengths are 2.57 Å. There is one shorter (2.56 Å) and one longer (2.57 Å) Cr(5)-Si(4) bond length. In the sixth Cr site, Cr(6) is bonded in a 6-coordinate geometry to two equivalent Ti(3), two equivalent Cr(2), two equivalent Cr(3), one Si(1), one Si(2), and two equivalent Si(3) atoms. The Cr(6)-Si(1) bond length is 2.58 Å. The Cr(6)-Si(2) bond length is 2.63 Å. Both Cr(6)-Si(3) bond lengths are 2.58 Å. In the seventh Cr site, Cr(7) is bonded in a 14-coordinate geometry to two equivalent Ti(1), two equivalent Cr(1), two equivalent Cr(2), two equivalent Cr(3), two equivalent Cr(5), one Si(1), one Si(2), and two equivalent Si(4) atoms. The Cr(7)-Si(1) bond length is 2.57 Å. The Cr(7)-Si(2) bond length is 2.54 Å. Both Cr(7)-Si(4) bond lengths are 2.58 Å. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one Ti(3), two equivalent Ti(1), one Cr(1), one Cr(6), one Cr(7), two equivalent Cr(4), and four equivalent Cr(2) atoms to form SiTi3Cr9 cuboctahedra that share edges with two equivalent Si(2)Ti3Cr9 cuboctahedra, edges with four equivalent Si(1)Ti3Cr9 cuboctahedra, faces with four equivalent Si(4)Ti2Cr10 cuboctahedra, and faces with four equivalent Si(3)Ti4Cr8 cuboctahedra. In the second Si site, Si(2) is bonded to one Ti(3), two equivalent Ti(2), one Cr(1), one Cr(6), one Cr(7), two equivalent Cr(5), and four equivalent Cr(3) atoms to form SiTi3Cr9 cuboctahedra that share edges with two equivalent Si(1)Ti3Cr9 cuboctahedra, edges with four equivalent Si(2)Ti3Cr9 cuboctahedra, faces with four equivalent Si(4)Ti2Cr10 cuboctahedra, and faces with four equivalent Si(3)Ti4Cr8 cuboctahedra. In the third Si site, Si(3) is bonded to two equivalent Ti(2), two equivalent Ti(3), two equivalent Cr(2), two equivalent Cr(3), two equivalent Cr(4), and two equivalent Cr(6) atoms to form SiTi4Cr8 cuboctahedra that share edges with two equivalent Si(4)Ti2Cr10 cuboctahedra, edges with four equivalent Si(3)Ti4Cr8 cuboctahedra, faces with four equivalent Si(1)Ti3Cr9 cuboctahedra, and faces with four equivalent Si(2)Ti3Cr9 cuboctahedra. In the fourth Si site, Si(4) is bonded to two equivalent Ti(1), two equivalent Cr(1), two equivalent Cr(2), two equivalent Cr(3), two equivalent Cr(5), and two equivalent Cr(7) atoms to form SiTi2Cr10 cuboctahedra that share edges with two equivalent Si(3)Ti4Cr8 cuboctahedra, edges with four equivalent Si(4)Ti2Cr10 cuboctahedra, faces with four equivalent Si(1)Ti3Cr9 cuboctahedra, and faces with four equivalent Si(2)Ti3Cr9 cuboctahedra.