SrCaMg6O8 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. Sr(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form SrO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Sr(1)O6 octahedra, edges with four equivalent Ca(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. Ca(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form CaO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Ca(1)O6 octahedra, edges with four equivalent Sr(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Sr(1)O6 octahedra, corners with four equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. In the third Mg site, Mg(3) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Mg(3)O6 octahedra, edges with two equivalent Sr(1)O6 octahedra, edges with two equivalent Ca(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Mg(1), and four equivalent Mg(3) atoms to form OCaMg5 octahedra that share corners with six equivalent O(1)CaMg5 octahedra, edges with four equivalent O(4)Mg6 octahedra, edges with four equivalent O(3)Sr2Ca2Mg2 octahedra, and edges with four equivalent O(2)SrMg5 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second O site, O(2) is bonded to one Sr(1), one Mg(2), and four equivalent Mg(3) atoms to form OSrMg5 octahedra that share corners with six equivalent O(2)SrMg5 octahedra, edges with four equivalent O(1)CaMg5 octahedra, edges with four equivalent O(4)Mg6 octahedra, and edges with four equivalent O(3)Sr2Ca2Mg2 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Ca(1), and two equivalent Mg(3) atoms to form OSr2Ca2Mg2 octahedra that share corners with two equivalent O(4)Mg6 octahedra, corners with four equivalent O(3)Sr2Ca2Mg2 octahedra, edges with four equivalent O(1)CaMg5 octahedra, edges with four equivalent O(3)Sr2Ca2Mg2 octahedra, and edges with four equivalent O(2)SrMg5 octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(3)Sr2Ca2Mg2 octahedra, corners with four equivalent O(4)Mg6 octahedra, edges with four equivalent O(1)CaMg5 octahedra, edges with four equivalent O(4)Mg6 octahedra, and edges with four equivalent O(2)SrMg5 octahedra. The corner-sharing octahedra are not tilted.
SrCaMg6O8 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. Sr(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form SrO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Sr(1)O6 octahedra, edges with four equivalent Ca(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. Both Sr(1)-O(2) bond lengths are 2.43 Å. All Sr(1)-O(3) bond lengths are 2.29 Å. Ca(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form CaO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Ca(1)O6 octahedra, edges with four equivalent Sr(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. Both Ca(1)-O(1) bond lengths are 2.37 Å. All Ca(1)-O(3) bond lengths are 2.29 Å. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. Both Mg(1)-O(1) bond lengths are 2.07 Å. All Mg(1)-O(4) bond lengths are 2.29 Å. In the second Mg site, Mg(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Sr(1)O6 octahedra, corners with four equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. Both Mg(2)-O(2) bond lengths are 2.01 Å. All Mg(2)-O(4) bond lengths are 2.29 Å. In the third Mg site, Mg(3) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Mg(3)O6 octahedra, edges with two equivalent Sr(1)O6 octahedra, edges with two equivalent Ca(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. The Mg(3)-O(3) bond length is 2.38 Å. The Mg(3)-O(4) bond length is 2.06 Å. Both Mg(3)-O(1) bond lengths are 2.29 Å. Both Mg(3)-O(2) bond lengths are 2.29 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Mg(1), and four equivalent Mg(3) atoms to form OCaMg5 octahedra that share corners with six equivalent O(1)CaMg5 octahedra, edges with four equivalent O(4)Mg6 octahedra, edges with four equivalent O(3)Sr2Ca2Mg2 octahedra, and edges with four equivalent O(2)SrMg5 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second O site, O(2) is bonded to one Sr(1), one Mg(2), and four equivalent Mg(3) atoms to form OSrMg5 octahedra that share corners with six equivalent O(2)SrMg5 octahedra, edges with four equivalent O(1)CaMg5 octahedra, edges with four equivalent O(4)Mg6 octahedra, and edges with four equivalent O(3)Sr2Ca2Mg2 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Ca(1), and two equivalent Mg(3) atoms to form OSr2Ca2Mg2 octahedra that share corners with two equivalent O(4)Mg6 octahedra, corners with four equivalent O(3)Sr2Ca2Mg2 octahedra, edges with four equivalent O(1)CaMg5 octahedra, edges with four equivalent O(3)Sr2Ca2Mg2 octahedra, and edges with four equivalent O(2)SrMg5 octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(3)Sr2Ca2Mg2 octahedra, corners with four equivalent O(4)Mg6 octahedra, edges with four equivalent O(1)CaMg5 octahedra, edges with four equivalent O(4)Mg6 octahedra, and edges with four equivalent O(2)SrMg5 octahedra. The corner-sharing octahedra are not tilted.