Materials Data on SrAl12O19 by Materials Project

SrAl12O19 crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with six equivalent SrO12 cuboctahedra, edges with six AlO6 octahedra, edges with three equivalent AlO5 trigonal bipyramids, and faces with six AlO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.75–2.81 Å. There are eight inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–60°. There is three shorter (1.81 Å) and one longer (1.84 Å) Al–O bond length. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–60°. All Al–O bond lengths are 1.82 Å. In the third Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six equivalent AlO6 octahedra, corners with three equivalent AlO5 trigonal bipyramids, faces with three equivalent SrO12 cuboctahedra, and a faceface with one AlO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There is three shorter (1.89 Å) and three longer (2.00 Å) Al–O bond length. In the fourth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six equivalent AlO6 octahedra, corners with three equivalent AlO5 trigonal bipyramids, faces with three equivalent SrO12 cuboctahedra, and a faceface with one AlO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There is three shorter (1.90 Å) and three longer (1.97 Å) Al–O bond length. In the fifth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six AlO4 tetrahedra and edges with six AlO6 octahedra. There is three shorter (1.89 Å) and three longer (1.90 Å) Al–O bond length. In the sixth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO6 octahedra, corners with three AlO4 tetrahedra, a cornercorner with one AlO5 trigonal bipyramid, an edgeedge with one SrO12 cuboctahedra, and edges with five AlO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are a spread of Al–O bond distances ranging from 1.83–2.01 Å. In the seventh Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO6 octahedra, corners with three AlO4 tetrahedra, a cornercorner with one AlO5 trigonal bipyramid, an edgeedge with one SrO12 cuboctahedra, and edges with five AlO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are a spread of Al–O bond distances ranging from 1.83–2.03 Å. In the eighth Al3+ site, Al3+ is bonded to five O2- atoms to form distorted AlO5 trigonal bipyramids that share corners with twelve AlO6 octahedra and edges with three equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 37–62°. There are a spread of Al–O bond distances ranging from 1.77–2.46 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+ and three Al3+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+ and three Al3+ atoms. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to four Al3+ atoms. In the eighth O2- site, O2- is bonded in a distorted tetrahedral geometry to four Al3+ atoms. In the ninth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three Al3+ atoms.

六铝酸锶（SrAl₁₂O₁₉）结晶于六方P6₃mc空间群（space group），其结构为三维框架结构。Sr²+与12个O²-配位形成SrO₁₂立方八面体（cuboctahedron），该多面体分别与6个等价的SrO₁₂立方八面体共享顶点、与6个AlO₆八面体（octahedron）共享棱边、与3个等价的AlO₅三角双锥（trigonal bipyramid）共享棱边，同时与6个AlO₆八面体共享面。Sr-O键的键长（bond length）分布范围为2.75~2.81 埃（ångström，符号Å）。
体系中存在8个不等价的Al³+配位位点：
1. 首个Al³+位点中，Al³+与4个O²-配位形成AlO₄四面体（tetrahedron）并共享顶点，共享顶点的八面体倾斜角范围为53°~60°，其Al-O键长包含3个较短的1.81 Å与1个较长的1.84 Å。
2. 第二个Al³+位点中，Al³+与4个O²-配位形成AlO₄四面体并共享顶点，共享顶点的八面体倾斜角范围为53°~60°，所有Al-O键长均为1.82 Å。
3. 第三个Al³+位点中，Al³+与6个O²-配位形成AlO₆八面体，该八面体与6个等价的AlO₆八面体共享顶点、与3个等价的AlO₅三角双锥共享顶点、与3个等价的SrO₁₂立方八面体共享面，同时与1个AlO₆八面体共享面。共享顶点的八面体倾斜角为52°，其Al-O键长包含3个较短的1.89 Å与3个较长的2.00 Å。
4. 第四个Al³+位点中，Al³+与6个O²-配位形成AlO₆八面体，该八面体与6个等价的AlO₆八面体共享顶点、与3个等价的AlO₅三角双锥共享顶点、与3个等价的SrO₁₂立方八面体共享面，同时与1个AlO₆八面体共享面。共享顶点的八面体倾斜角为52°，其Al-O键长包含3个较短的1.90 Å与3个较长的1.97 Å。
5. 第五个Al³+位点中，Al³+与6个O²-配位形成AlO₆八面体，该八面体与6个AlO₄四面体共享顶点、与6个AlO₆八面体共享棱边，其Al-O键长包含3个较短的1.89 Å与3个较长的1.90 Å。
6. 第六个Al³+位点中，Al³+与6个O²-配位形成AlO₆八面体，该八面体与2个等价的AlO₆八面体共享顶点、与3个AlO₄四面体共享顶点、与1个AlO₅三角双锥共享顶点、与1个SrO₁₂立方八面体共享棱边，同时与5个AlO₆八面体共享棱边。共享顶点的八面体倾斜角为52°，Al-O键长分布范围为1.83~2.01 Å。
7. 第七个Al³+位点中，Al³+与6个O²-配位形成AlO₆八面体，该八面体与2个等价的AlO₆八面体共享顶点、与3个AlO₄四面体共享顶点、与1个AlO₅三角双锥共享顶点、与1个SrO₁₂立方八面体共享棱边，同时与5个AlO₆八面体共享棱边。共享顶点的八面体倾斜角为52°，Al-O键长分布范围为1.83~2.03 Å。
8. 第八个Al³+位点中，Al³+与5个O²-配位形成畸变的AlO₅三角双锥，该多面体与12个AlO₆八面体共享顶点、与3个等价的SrO₁₂立方八面体共享棱边。共享顶点的八面体倾斜角范围为37°~62°，Al-O键长分布范围为1.77~2.46 Å。
体系中同时存在9个不等价的O²-配位位点：
1. 首个O²-位点中，O²-为3配位构型，与1个Sr²+和3个Al³+相连。
2. 第二个O²-位点中，O²-为3配位构型，与1个Sr²+和3个Al³+相连。
3. 第三个O²-位点中，O²-为矩形跷跷板状配位构型，与4个Al³+相连。
4. 第四个O²-位点中，O²-为矩形跷跷板状配位构型，与4个Al³+相连。
5. 第五个O²-位点中，O²-为矩形跷跷板状配位构型，与4个Al³+相连。
6. 第六个O²-位点中，O²-为矩形跷跷板状配位构型，与4个Al³+相连。
7. 第七个O²-位点中，O²-为4配位构型，与4个Al³+相连。
8. 第八个O²-位点中，O²-为畸变四面体配位构型，与4个Al³+相连。
9. 第九个O²-位点中，O²-为5配位构型，与2个等价的Sr²+和3个Al³+相连。