Nb7Mn5N2 crystallizes in the orthorhombic Imma space group. There are four inequivalent Nb sites. In the first Nb site, Nb(4) is bonded to two equivalent Mn(2) and four equivalent Mn(1) atoms to form distorted NbMn6 cuboctahedra that share edges with two equivalent Nb(4)Mn6 cuboctahedra, edges with two equivalent Mn(2)Mn5Nb7 cuboctahedra, edges with four equivalent Mn(3)Mn6Nb6 cuboctahedra, and faces with two equivalent Mn(2)Mn5Nb7 cuboctahedra. In the second Nb site, Nb(1) is bonded in a bent 150 degrees geometry to two equivalent Mn(1), two equivalent Mn(2), and two equivalent N(1) atoms. In the third Nb site, Nb(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Mn(1), two equivalent Mn(2), two equivalent Mn(3), and two equivalent N(2) atoms. In the fourth Nb site, Nb(3) is bonded in a distorted bent 150 degrees geometry to one Mn(3), two equivalent Mn(1), two equivalent Mn(2), one N(1), and one N(2) atom. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 12-coordinate geometry to one Nb(1), one Nb(2), two equivalent Nb(4), four equivalent Nb(3), one Mn(1), one Mn(3), and two equivalent Mn(2) atoms. In the second Mn site, Mn(2) is bonded to one Nb(1), one Nb(2), one Nb(4), four equivalent Nb(3), one Mn(2), two equivalent Mn(1), and two equivalent Mn(3) atoms to form distorted MnMn5Nb7 cuboctahedra that share corners with four equivalent Mn(2)Mn5Nb7 cuboctahedra, corners with three equivalent N(2)Nb6 octahedra,  an edgeedge with one Nb(4)Mn6 cuboctahedra,  a faceface with one Nb(4)Mn6 cuboctahedra, faces with two equivalent Mn(3)Mn6Nb6 cuboctahedra, faces with three equivalent Mn(2)Mn5Nb7 cuboctahedra,  a faceface with one N(2)Nb6 octahedra, and faces with two equivalent N(1)Nb6 octahedra. The corner-sharing octahedral tilt angles range from 42-43°. In the third Mn site, Mn(3) is bonded to two equivalent Nb(2), four equivalent Nb(3), two equivalent Mn(1), and four equivalent Mn(2) atoms to form MnMn6Nb6 cuboctahedra that share edges with four equivalent Nb(4)Mn6 cuboctahedra, edges with two equivalent N(1)Nb6 octahedra, edges with four equivalent N(2)Nb6 octahedra, faces with two equivalent Mn(3)Mn6Nb6 cuboctahedra, and faces with four equivalent Mn(2)Mn5Nb7 cuboctahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Nb(1) and four equivalent Nb(3) atoms to form NNb6 octahedra that share corners with two equivalent N(1)Nb6 octahedra, corners with four equivalent N(2)Nb6 octahedra, edges with two equivalent Mn(3)Mn6Nb6 cuboctahedra, and faces with four equivalent Mn(2)Mn5Nb7 cuboctahedra. The corner-sharing octahedral tilt angles range from 38-42°. In the second N site, N(2) is bonded to two equivalent Nb(2) and four equivalent Nb(3) atoms to form NNb6 octahedra that share corners with six equivalent Mn(2)Mn5Nb7 cuboctahedra, corners with two equivalent N(2)Nb6 octahedra, corners with four equivalent N(1)Nb6 octahedra, edges with four equivalent Mn(3)Mn6Nb6 cuboctahedra, and faces with two equivalent Mn(2)Mn5Nb7 cuboctahedra. The corner-sharing octahedral tilt angles range from 42-44°.
Nb7Mn5N2 crystallizes in the orthorhombic Imma space group. There are four inequivalent Nb sites. In the first Nb site, Nb(4) is bonded to two equivalent Mn(2) and four equivalent Mn(1) atoms to form distorted NbMn6 cuboctahedra that share edges with two equivalent Nb(4)Mn6 cuboctahedra, edges with two equivalent Mn(2)Mn5Nb7 cuboctahedra, edges with four equivalent Mn(3)Mn6Nb6 cuboctahedra, and faces with two equivalent Mn(2)Mn5Nb7 cuboctahedra. Both Nb(4)-Mn(2) bond lengths are 2.55 Å. All Nb(4)-Mn(1) bond lengths are 2.52 Å. In the second Nb site, Nb(1) is bonded in a bent 150 degrees geometry to two equivalent Mn(1), two equivalent Mn(2), and two equivalent N(1) atoms. Both Nb(1)-Mn(1) bond lengths are 3.09 Å. Both Nb(1)-Mn(2) bond lengths are 2.86 Å. Both Nb(1)-N(1) bond lengths are 2.17 Å. In the third Nb site, Nb(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Mn(1), two equivalent Mn(2), two equivalent Mn(3), and two equivalent N(2) atoms. Both Nb(2)-Mn(1) bond lengths are 2.74 Å. Both Nb(2)-Mn(2) bond lengths are 2.83 Å. Both Nb(2)-Mn(3) bond lengths are 2.91 Å. Both Nb(2)-N(2) bond lengths are 2.20 Å. In the fourth Nb site, Nb(3) is bonded in a distorted bent 150 degrees geometry to one Mn(3), two equivalent Mn(1), two equivalent Mn(2), one N(1), and one N(2) atom. The Nb(3)-Mn(3) bond length is 2.91 Å. There is one shorter (2.85 Å) and one longer (2.89 Å) Nb(3)-Mn(1) bond length. There is one shorter (2.78 Å) and one longer (2.99 Å) Nb(3)-Mn(2) bond length. The Nb(3)-N(1) bond length is 2.19 Å. The Nb(3)-N(2) bond length is 2.19 Å. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 12-coordinate geometry to one Nb(1), one Nb(2), two equivalent Nb(4), four equivalent Nb(3), one Mn(1), one Mn(3), and two equivalent Mn(2) atoms. The Mn(1)-Mn(1) bond length is 2.74 Å. The Mn(1)-Mn(3) bond length is 2.40 Å. Both Mn(1)-Mn(2) bond lengths are 2.58 Å. In the second Mn site, Mn(2) is bonded to one Nb(1), one Nb(2), one Nb(4), four equivalent Nb(3), one Mn(2), two equivalent Mn(1), and two equivalent Mn(3) atoms to form distorted MnMn5Nb7 cuboctahedra that share corners with four equivalent Mn(2)Mn5Nb7 cuboctahedra, corners with three equivalent N(2)Nb6 octahedra,  an edgeedge with one Nb(4)Mn6 cuboctahedra,  a faceface with one Nb(4)Mn6 cuboctahedra, faces with two equivalent Mn(3)Mn6Nb6 cuboctahedra, faces with three equivalent Mn(2)Mn5Nb7 cuboctahedra,  a faceface with one N(2)Nb6 octahedra, and faces with two equivalent N(1)Nb6 octahedra. The corner-sharing octahedral tilt angles range from 42-43°. The Mn(2)-Mn(2) bond length is 2.44 Å. Both Mn(2)-Mn(3) bond lengths are 2.43 Å. In the third Mn site, Mn(3) is bonded to two equivalent Nb(2), four equivalent Nb(3), two equivalent Mn(1), and four equivalent Mn(2) atoms to form MnMn6Nb6 cuboctahedra that share edges with four equivalent Nb(4)Mn6 cuboctahedra, edges with two equivalent N(1)Nb6 octahedra, edges with four equivalent N(2)Nb6 octahedra, faces with two equivalent Mn(3)Mn6Nb6 cuboctahedra, and faces with four equivalent Mn(2)Mn5Nb7 cuboctahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Nb(1) and four equivalent Nb(3) atoms to form NNb6 octahedra that share corners with two equivalent N(1)Nb6 octahedra, corners with four equivalent N(2)Nb6 octahedra, edges with two equivalent Mn(3)Mn6Nb6 cuboctahedra, and faces with four equivalent Mn(2)Mn5Nb7 cuboctahedra. The corner-sharing octahedral tilt angles range from 38-42°. In the second N site, N(2) is bonded to two equivalent Nb(2) and four equivalent Nb(3) atoms to form NNb6 octahedra that share corners with six equivalent Mn(2)Mn5Nb7 cuboctahedra, corners with two equivalent N(2)Nb6 octahedra, corners with four equivalent N(1)Nb6 octahedra, edges with four equivalent Mn(3)Mn6Nb6 cuboctahedra, and faces with two equivalent Mn(2)Mn5Nb7 cuboctahedra. The corner-sharing octahedral tilt angles range from 42-44°.