KNdMn4O12 crystallizes in the orthorhombic Amm2 space group. K(1) is bonded to two equivalent O(2), two equivalent O(3), four equivalent O(1), and four equivalent O(4) atoms to form distorted KO12 cuboctahedra that share corners with four equivalent K(1)O12 cuboctahedra, corners with eight equivalent Nd(1)O12 cuboctahedra, and faces with eight equivalent Mn(1)O6 octahedra. Nd(1) is bonded to two equivalent O(2), two equivalent O(3), four equivalent O(1), and four equivalent O(5) atoms to form distorted NdO12 cuboctahedra that share corners with four equivalent Nd(1)O12 cuboctahedra, corners with eight equivalent K(1)O12 cuboctahedra, and faces with eight equivalent Mn(1)O6 octahedra. Mn(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form MnO6 octahedra that share corners with six equivalent Mn(1)O6 octahedra, faces with two equivalent K(1)O12 cuboctahedra, and faces with two equivalent Nd(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 10-20°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one Nd(1), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one Nd(1), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded in a 2-coordinate geometry to one K(1), one Nd(1), and two equivalent Mn(1) atoms. In the fourth O site, O(4) is bonded in a distorted square co-planar geometry to two equivalent K(1) and two equivalent Mn(1) atoms. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent Nd(1) and two equivalent Mn(1) atoms.
KNdMn4O12 crystallizes in the orthorhombic Amm2 space group. K(1) is bonded to two equivalent O(2), two equivalent O(3), four equivalent O(1), and four equivalent O(4) atoms to form distorted KO12 cuboctahedra that share corners with four equivalent K(1)O12 cuboctahedra, corners with eight equivalent Nd(1)O12 cuboctahedra, and faces with eight equivalent Mn(1)O6 octahedra. Both K(1)-O(2) bond lengths are 3.03 Å. Both K(1)-O(3) bond lengths are 2.81 Å. All K(1)-O(1) bond lengths are 2.76 Å. There are two shorter (2.64 Å) and two longer (2.76 Å) K(1)-O(4) bond lengths. Nd(1) is bonded to two equivalent O(2), two equivalent O(3), four equivalent O(1), and four equivalent O(5) atoms to form distorted NdO12 cuboctahedra that share corners with four equivalent Nd(1)O12 cuboctahedra, corners with eight equivalent K(1)O12 cuboctahedra, and faces with eight equivalent Mn(1)O6 octahedra. Both Nd(1)-O(2) bond lengths are 2.46 Å. Both Nd(1)-O(3) bond lengths are 2.54 Å. All Nd(1)-O(1) bond lengths are 2.64 Å. There are two shorter (2.52 Å) and two longer (2.87 Å) Nd(1)-O(5) bond lengths. Mn(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form MnO6 octahedra that share corners with six equivalent Mn(1)O6 octahedra, faces with two equivalent K(1)O12 cuboctahedra, and faces with two equivalent Nd(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 10-20°. The Mn(1)-O(2) bond length is 1.92 Å. The Mn(1)-O(3) bond length is 1.92 Å. The Mn(1)-O(4) bond length is 1.87 Å. The Mn(1)-O(5) bond length is 1.97 Å. There is one shorter (1.92 Å) and one longer (1.93 Å) Mn(1)-O(1) bond length. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one Nd(1), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one Nd(1), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded in a 2-coordinate geometry to one K(1), one Nd(1), and two equivalent Mn(1) atoms. In the fourth O site, O(4) is bonded in a distorted square co-planar geometry to two equivalent K(1) and two equivalent Mn(1) atoms. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent Nd(1) and two equivalent Mn(1) atoms.