Sr2CaAlO4F crystallizes in the orthorhombic Fmmm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted q6 geometry to four equivalent O(1), four equivalent O(2), and two equivalent F(1) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(1), four equivalent O(2), and two equivalent F(1) atoms. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), four equivalent O(1), and two equivalent F(1) atoms. Al(1) is bonded in a tetrahedral geometry to two equivalent O(1) and two equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Sr(2), two equivalent Sr(1), two equivalent Ca(1), and one Al(1) atom to form distorted OSr3Ca2Al octahedra that share corners with four equivalent O(1)Sr3Ca2Al octahedra, corners with four equivalent F(1)Sr4Ca2 octahedra, edges with two equivalent O(1)Sr3Ca2Al octahedra, faces with two equivalent O(1)Sr3Ca2Al octahedra, and faces with two equivalent F(1)Sr4Ca2 octahedra. The corner-sharing octahedral tilt angles range from 44-66°. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one Ca(1), and one Al(1) atom. F(1) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Ca(1) atoms to form FSr4Ca2 octahedra that share corners with six equivalent F(1)Sr4Ca2 octahedra, corners with eight equivalent O(1)Sr3Ca2Al octahedra, and faces with four equivalent O(1)Sr3Ca2Al octahedra. The corner-sharing octahedral tilt angles range from 0-66°.
Sr2CaAlO4F crystallizes in the orthorhombic Fmmm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted q6 geometry to four equivalent O(1), four equivalent O(2), and two equivalent F(1) atoms. All Sr(1)-O(1) bond lengths are 2.82 Å. All Sr(1)-O(2) bond lengths are 2.84 Å. Both Sr(1)-F(1) bond lengths are 2.77 Å. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(1), four equivalent O(2), and two equivalent F(1) atoms. Both Sr(2)-O(1) bond lengths are 2.45 Å. All Sr(2)-O(2) bond lengths are 2.67 Å. Both Sr(2)-F(1) bond lengths are 2.47 Å. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), four equivalent O(1), and two equivalent F(1) atoms. Both Ca(1)-O(2) bond lengths are 2.35 Å. All Ca(1)-O(1) bond lengths are 2.64 Å. Both Ca(1)-F(1) bond lengths are 2.52 Å. Al(1) is bonded in a tetrahedral geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Al(1)-O(1) bond lengths are 1.78 Å. Both Al(1)-O(2) bond lengths are 1.80 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Sr(2), two equivalent Sr(1), two equivalent Ca(1), and one Al(1) atom to form distorted OSr3Ca2Al octahedra that share corners with four equivalent O(1)Sr3Ca2Al octahedra, corners with four equivalent F(1)Sr4Ca2 octahedra, edges with two equivalent O(1)Sr3Ca2Al octahedra, faces with two equivalent O(1)Sr3Ca2Al octahedra, and faces with two equivalent F(1)Sr4Ca2 octahedra. The corner-sharing octahedral tilt angles range from 44-66°. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one Ca(1), and one Al(1) atom. F(1) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Ca(1) atoms to form FSr4Ca2 octahedra that share corners with six equivalent F(1)Sr4Ca2 octahedra, corners with eight equivalent O(1)Sr3Ca2Al octahedra, and faces with four equivalent O(1)Sr3Ca2Al octahedra. The corner-sharing octahedral tilt angles range from 0-66°.