Mn6Si7 is Frank-Kasper $\mu$ Phase structured and crystallizes in the trigonal R-3m space group. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 6-coordinate geometry to six equivalent Si(2) atoms. In the second Mn site, Mn(2) is bonded in a 16-coordinate geometry to one Mn(3), three equivalent Mn(2), three equivalent Si(1), and nine equivalent Si(2) atoms. In the third Mn site, Mn(3) is bonded in a 8-coordinate geometry to one Mn(2), one Mn(3), and six equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to six equivalent Mn(2) and six equivalent Si(2) atoms to form edge-sharing SiMn6Si6 cuboctahedra. In the second Si site, Si(2) is bonded in a 12-coordinate geometry to two equivalent Mn(1), two equivalent Mn(3), three equivalent Mn(2), one Si(1), and four equivalent Si(2) atoms.
Mn6Si7 is Frank-Kasper $\mu$ Phase structured and crystallizes in the trigonal R-3m space group. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 6-coordinate geometry to six equivalent Si(2) atoms. There are three shorter (2.41 Å) and three longer (2.44 Å) Mn(1)-Si(2) bond lengths. In the second Mn site, Mn(2) is bonded in a 16-coordinate geometry to one Mn(3), three equivalent Mn(2), three equivalent Si(1), and nine equivalent Si(2) atoms. The Mn(2)-Mn(3) bond length is 2.69 Å. All Mn(2)-Mn(2) bond lengths are 2.81 Å. All Mn(2)-Si(1) bond lengths are 2.80 Å. There are three shorter (2.51 Å) and six longer (3.07 Å) Mn(2)-Si(2) bond lengths. In the third Mn site, Mn(3) is bonded in a 8-coordinate geometry to one Mn(2), one Mn(3), and six equivalent Si(2) atoms. The Mn(3)-Mn(3) bond length is 2.34 Å. All Mn(3)-Si(2) bond lengths are 2.56 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to six equivalent Mn(2) and six equivalent Si(2) atoms to form edge-sharing SiMn6Si6 cuboctahedra. All Si(1)-Si(2) bond lengths are 2.44 Å. In the second Si site, Si(2) is bonded in a 12-coordinate geometry to two equivalent Mn(1), two equivalent Mn(3), three equivalent Mn(2), one Si(1), and four equivalent Si(2) atoms. There are two shorter (2.39 Å) and two longer (2.46 Å) Si(2)-Si(2) bond lengths.