The material structure described by SrCaAl4(SiO5)4 crystallizes in the monoclinic Pm space group. Sr(1) is bonded in a 6-coordinate geometry to one O(3), one O(7), two equivalent O(12), and two equivalent O(6) atoms. Ca(1) is bonded in a 6-coordinate geometry to one O(4), one O(8), two equivalent O(11), and two equivalent O(5) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(10), one O(11), one O(12), one O(2), and one O(9) atom to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Al(2)O6 octahedra. In the second Al site, Al(2) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Al(1)O6 octahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(11), one O(5), one O(8), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-60°. In the second Si site, Si(2) is bonded to one O(10), one O(12), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-59°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one Al(1) and one Al(2) atom. In the second O site, O(2) is bonded in a water-like geometry to one Al(1) and one Al(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Sr(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one Ca(1) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Ca(1), one Al(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Sr(1), one Al(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Sr(1) and two equivalent Si(2) atoms. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Ca(1) and two equivalent Si(1) atoms. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Al(1), one Al(2), and one Si(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Al(1), one Al(2), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Ca(1), one Al(1), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Sr(1), one Al(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_SrCaAl4(SiO5)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.114
_cell_length_b   5.353
_cell_length_c   5.394
_cell_angle_alpha   66.905
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   348.272
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Sr  Sr0  1  0.500  0.682  0.662  1.0
  Ca  Ca1  1  0.000  0.331  0.342  1.0
  Al  Al2  1  0.752  0.001  0.499  1.0
  Al  Al3  1  0.248  0.001  0.499  1.0
  Al  Al4  1  0.752  0.499  0.001  1.0
  Al  Al5  1  0.248  0.499  0.001  1.0
  Si  Si6  1  0.881  0.985  0.974  1.0
  Si  Si7  1  0.378  0.016  0.026  1.0
  Si  Si8  1  0.622  0.016  0.026  1.0
  Si  Si9  1  0.119  0.985  0.974  1.0
  O  O10  1  0.811  0.649  0.653  1.0
  O  O11  1  0.309  0.350  0.347  1.0
  O  O12  1  0.691  0.350  0.347  1.0
  O  O13  1  0.189  0.649  0.653  1.0
  O  O14  1  0.500  0.323  0.430  1.0
  O  O15  1  0.000  0.659  0.563  1.0
  O  O16  1  0.867  0.654  0.099  1.0
  O  O17  1  0.361  0.344  0.902  1.0
  O  O18  1  0.639  0.344  0.902  1.0
  O  O19  1  0.133  0.654  0.099  1.0
  O  O20  1  0.500  0.953  0.981  1.0
  O  O21  1  0.000  0.056  0.032  1.0
  O  O22  1  0.819  0.141  0.139  1.0
  O  O23  1  0.318  0.860  0.859  1.0
  O  O24  1  0.682  0.860  0.859  1.0
  O  O25  1  0.181  0.141  0.139  1.0
  O  O26  1  0.137  0.114  0.648  1.0
  O  O27  1  0.644  0.884  0.349  1.0
  O  O28  1  0.356  0.884  0.349  1.0
  O  O29  1  0.863  0.114  0.648  1.0
[/CIF]
.
The material structure described by SrCaAl4(SiO5)4 crystallizes in the monoclinic Pm space group. Sr(1) is bonded in a 6-coordinate geometry to one O(3), one O(7), two equivalent O(12), and two equivalent O(6) atoms. Ca(1) is bonded in a 6-coordinate geometry to one O(4), one O(8), two equivalent O(11), and two equivalent O(5) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(10), one O(11), one O(12), one O(2), and one O(9) atom to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Al(2)O6 octahedra. In the second Al site, Al(2) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Al(1)O6 octahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(11), one O(5), one O(8), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-60°. In the second Si site, Si(2) is bonded to one O(10), one O(12), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-59°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one Al(1) and one Al(2) atom. In the second O site, O(2) is bonded in a water-like geometry to one Al(1) and one Al(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Sr(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one Ca(1) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Ca(1), one Al(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Sr(1), one Al(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Sr(1) and two equivalent Si(2) atoms. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Ca(1) and two equivalent Si(1) atoms. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Al(1), one Al(2), and one Si(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Al(1), one Al(2), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Ca(1), one Al(1), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Sr(1), one Al(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_SrCaAl4(SiO5)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.114
_cell_length_b   5.353
_cell_length_c   5.394
_cell_angle_alpha   66.905
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   348.272
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Sr  Sr0  1  0.500  0.682  0.662  1.0
  Ca  Ca1  1  0.000  0.331  0.342  1.0
  Al  Al2  1  0.752  0.001  0.499  1.0
  Al  Al3  1  0.248  0.001  0.499  1.0
  Al  Al4  1  0.752  0.499  0.001  1.0
  Al  Al5  1  0.248  0.499  0.001  1.0
  Si  Si6  1  0.881  0.985  0.974  1.0
  Si  Si7  1  0.378  0.016  0.026  1.0
  Si  Si8  1  0.622  0.016  0.026  1.0
  Si  Si9  1  0.119  0.985  0.974  1.0
  O  O10  1  0.811  0.649  0.653  1.0
  O  O11  1  0.309  0.350  0.347  1.0
  O  O12  1  0.691  0.350  0.347  1.0
  O  O13  1  0.189  0.649  0.653  1.0
  O  O14  1  0.500  0.323  0.430  1.0
  O  O15  1  0.000  0.659  0.563  1.0
  O  O16  1  0.867  0.654  0.099  1.0
  O  O17  1  0.361  0.344  0.902  1.0
  O  O18  1  0.639  0.344  0.902  1.0
  O  O19  1  0.133  0.654  0.099  1.0
  O  O20  1  0.500  0.953  0.981  1.0
  O  O21  1  0.000  0.056  0.032  1.0
  O  O22  1  0.819  0.141  0.139  1.0
  O  O23  1  0.318  0.860  0.859  1.0
  O  O24  1  0.682  0.860  0.859  1.0
  O  O25  1  0.181  0.141  0.139  1.0
  O  O26  1  0.137  0.114  0.648  1.0
  O  O27  1  0.644  0.884  0.349  1.0
  O  O28  1  0.356  0.884  0.349  1.0
  O  O29  1  0.863  0.114  0.648  1.0
[/CIF]
.