Sr2YMn2O7 crystallizes in the orthorhombic Imma space group. Sr(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form distorted SrO6 pentagonal pyramids that share corners with six equivalent Sr(1)O6 pentagonal pyramids, corners with four equivalent Mn(1)O5 trigonal bipyramids, edges with three equivalent Sr(1)O6 pentagonal pyramids, and faces with two equivalent Sr(1)O6 pentagonal pyramids. Y(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. Mn(1) is bonded to one O(4), two equivalent O(2), and two equivalent O(3) atoms to form distorted MnO5 trigonal bipyramids that share corners with four equivalent Sr(1)O6 pentagonal pyramids and corners with four equivalent Mn(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a square co-planar geometry to four equivalent Sr(1) atoms. In the second O site, O(2) is bonded to two equivalent Y(1) and two equivalent Mn(1) atoms to form a mixture of distorted edge and corner-sharing OY2Mn2 tetrahedra. In the third O site, O(3) is bonded to two equivalent Y(1) and two equivalent Mn(1) atoms to form a mixture of distorted edge and corner-sharing OY2Mn2 tetrahedra. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to four equivalent Sr(1) and one Mn(1) atom.
Sr2YMn2O7 crystallizes in the orthorhombic Imma space group. Sr(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form distorted SrO6 pentagonal pyramids that share corners with six equivalent Sr(1)O6 pentagonal pyramids, corners with four equivalent Mn(1)O5 trigonal bipyramids, edges with three equivalent Sr(1)O6 pentagonal pyramids, and faces with two equivalent Sr(1)O6 pentagonal pyramids. Both Sr(1)-O(1) bond lengths are 2.50 Å. There are a spread of Sr(1)-O(4) bond distances ranging from 2.57-2.86 Å. Y(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. All Y(1)-O(2) bond lengths are 2.32 Å. All Y(1)-O(3) bond lengths are 2.38 Å. Mn(1) is bonded to one O(4), two equivalent O(2), and two equivalent O(3) atoms to form distorted MnO5 trigonal bipyramids that share corners with four equivalent Sr(1)O6 pentagonal pyramids and corners with four equivalent Mn(1)O5 trigonal bipyramids. The Mn(1)-O(4) bond length is 1.89 Å. Both Mn(1)-O(2) bond lengths are 1.96 Å. Both Mn(1)-O(3) bond lengths are 1.96 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a square co-planar geometry to four equivalent Sr(1) atoms. In the second O site, O(2) is bonded to two equivalent Y(1) and two equivalent Mn(1) atoms to form a mixture of distorted edge and corner-sharing OY2Mn2 tetrahedra. In the third O site, O(3) is bonded to two equivalent Y(1) and two equivalent Mn(1) atoms to form a mixture of distorted edge and corner-sharing OY2Mn2 tetrahedra. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to four equivalent Sr(1) and one Mn(1) atom.