Sc4Mn4Si7 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to one Si(1), two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms to form a mixture of distorted edge, face, and corner-sharing ScSi7 pentagonal bipyramids. In the second Sc site, Sc(2) is bonded in a 7-coordinate geometry to two equivalent Si(2), two equivalent Si(3), and three equivalent Si(4) atoms. Mn(1) is bonded in a 6-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and two equivalent Si(4) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 6-coordinate geometry to one Sc(1), four equivalent Mn(1), and one Si(1) atom. In the second Si site, Si(2) is bonded in a 10-coordinate geometry to four equivalent Sc(1), four equivalent Sc(2), and two equivalent Si(2) atoms. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to two equivalent Sc(1), two equivalent Sc(2), and four equivalent Mn(1) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to two equivalent Sc(1), three equivalent Sc(2), and four equivalent Mn(1) atoms.
Sc4Mn4Si7 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to one Si(1), two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms to form a mixture of distorted edge, face, and corner-sharing ScSi7 pentagonal bipyramids. The Sc(1)-Si(1) bond length is 2.84 Å. Both Sc(1)-Si(2) bond lengths are 2.88 Å. Both Sc(1)-Si(3) bond lengths are 2.89 Å. Both Sc(1)-Si(4) bond lengths are 2.72 Å. In the second Sc site, Sc(2) is bonded in a 7-coordinate geometry to two equivalent Si(2), two equivalent Si(3), and three equivalent Si(4) atoms. Both Sc(2)-Si(2) bond lengths are 2.88 Å. Both Sc(2)-Si(3) bond lengths are 2.74 Å. There are two shorter (2.89 Å) and one longer (2.92 Å) Sc(2)-Si(4) bond length. Mn(1) is bonded in a 6-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and two equivalent Si(4) atoms. Both Mn(1)-Si(1) bond lengths are 2.48 Å. Both Mn(1)-Si(3) bond lengths are 2.47 Å. Both Mn(1)-Si(4) bond lengths are 2.43 Å. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 6-coordinate geometry to one Sc(1), four equivalent Mn(1), and one Si(1) atom. The Si(1)-Si(1) bond length is 2.36 Å. In the second Si site, Si(2) is bonded in a 10-coordinate geometry to four equivalent Sc(1), four equivalent Sc(2), and two equivalent Si(2) atoms. There is one shorter (2.57 Å) and one longer (2.61 Å) Si(2)-Si(2) bond length. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to two equivalent Sc(1), two equivalent Sc(2), and four equivalent Mn(1) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to two equivalent Sc(1), three equivalent Sc(2), and four equivalent Mn(1) atoms.