Mn5SiB2 crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a distorted square co-planar geometry to four equivalent B(1) and two equivalent Si(1) atoms. In the second Mn site, Mn(2) is bonded to three equivalent B(1) and two equivalent Si(1) atoms to form a mixture of distorted edge, face, and corner-sharing MnSi2B3 trigonal bipyramids. B(1) is bonded in a 9-coordinate geometry to two equivalent Mn(1), six equivalent Mn(2), and one B(1) atom. Si(1) is bonded in a 10-coordinate geometry to two equivalent Mn(1) and eight equivalent Mn(2) atoms.
Mn5SiB2 crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a distorted square co-planar geometry to four equivalent B(1) and two equivalent Si(1) atoms. All Mn(1)-B(1) bond lengths are 2.21 Å. Both Mn(1)-Si(1) bond lengths are 2.58 Å. In the second Mn site, Mn(2) is bonded to three equivalent B(1) and two equivalent Si(1) atoms to form a mixture of distorted edge, face, and corner-sharing MnSi2B3 trigonal bipyramids. There are two shorter (2.15 Å) and one longer (2.19 Å) Mn(2)-B(1) bond length. Both Mn(2)-Si(1) bond lengths are 2.38 Å. B(1) is bonded in a 9-coordinate geometry to two equivalent Mn(1), six equivalent Mn(2), and one B(1) atom. The B(1)-B(1) bond length is 1.90 Å. Si(1) is bonded in a 10-coordinate geometry to two equivalent Mn(1) and eight equivalent Mn(2) atoms.