SrMnO3 crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 12-coordinate geometry to two equivalent O(2), two equivalent O(4), four equivalent O(1), and four equivalent O(3) atoms. In the second Sr site, Sr(2) is bonded to two equivalent O(2), two equivalent O(4), four equivalent O(1), and four equivalent O(3) atoms to form distorted SrO12 cuboctahedra that share corners with six equivalent Sr(2)O12 cuboctahedra, corners with six equivalent Mn(1)O6 octahedra, faces with two equivalent Sr(2)O12 cuboctahedra, and faces with six equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-17°. Mn(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with three equivalent Sr(2)O12 cuboctahedra, corners with three equivalent Mn(1)O6 octahedra, faces with three equivalent Sr(2)O12 cuboctahedra, and  a faceface with one Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-16°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a distorted L-shaped geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms.
SrMnO3 crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 12-coordinate geometry to two equivalent O(2), two equivalent O(4), four equivalent O(1), and four equivalent O(3) atoms. Both Sr(1)-O(2) bond lengths are 2.78 Å. Both Sr(1)-O(4) bond lengths are 2.81 Å. There are two shorter (2.73 Å) and two longer (2.82 Å) Sr(1)-O(1) bond lengths. There are two shorter (2.54 Å) and two longer (3.14 Å) Sr(1)-O(3) bond lengths. In the second Sr site, Sr(2) is bonded to two equivalent O(2), two equivalent O(4), four equivalent O(1), and four equivalent O(3) atoms to form distorted SrO12 cuboctahedra that share corners with six equivalent Sr(2)O12 cuboctahedra, corners with six equivalent Mn(1)O6 octahedra, faces with two equivalent Sr(2)O12 cuboctahedra, and faces with six equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-17°. Both Sr(2)-O(2) bond lengths are 2.89 Å. There is one shorter (2.59 Å) and one longer (2.97 Å) Sr(2)-O(4) bond length. There are two shorter (2.73 Å) and two longer (3.10 Å) Sr(2)-O(1) bond lengths. There are two shorter (2.68 Å) and two longer (2.88 Å) Sr(2)-O(3) bond lengths. Mn(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with three equivalent Sr(2)O12 cuboctahedra, corners with three equivalent Mn(1)O6 octahedra, faces with three equivalent Sr(2)O12 cuboctahedra, and  a faceface with one Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-16°. The Mn(1)-O(2) bond length is 1.94 Å. The Mn(1)-O(4) bond length is 1.92 Å. There is one shorter (1.90 Å) and one longer (1.98 Å) Mn(1)-O(1) bond length. There is one shorter (1.90 Å) and one longer (1.95 Å) Mn(1)-O(3) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a distorted L-shaped geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms.