The compound described by Ca2MgAl2Si3O14 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), two equivalent O(5), and two equivalent O(7) atoms. In the second Ca site, Ca(2) is bonded to one O(11), one O(8), one O(9), two equivalent O(1), and two equivalent O(5) atoms to form distorted CaO7 pentagonal bipyramids that share corners with two equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(3)O4 tetrahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and  an edgeedge with one Si(2)O4 tetrahedra. Mg(1) is bonded to two equivalent O(11), two equivalent O(2), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Ca(2)O7 pentagonal bipyramids. Al(1) is bonded to one O(1), one O(10), one O(3), one O(6), one O(7), and one O(8) atom to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, edges with two equivalent Al(1)O6 octahedra, and  an edgeedge with one Ca(2)O7 pentagonal bipyramid. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(10), one O(2), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Al(1)O6 octahedra, and corners with two equivalent Ca(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 48-55°. In the second Si site, Si(2) is bonded to one O(8), one O(9), and two equivalent O(7) atoms to form SiO4 tetrahedra that share corners with four equivalent Al(1)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  an edgeedge with one Ca(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 51-55°. In the third Si site, Si(3) is bonded to one O(4), one O(9), and two equivalent O(5) atoms to form SiO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with three equivalent Ca(2)O7 pentagonal bipyramids, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 56°. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(2), one Al(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), two equivalent Mg(1), and one Si(1) atom. In the third O site, O(11) is bonded in a trigonal non-coplanar geometry to one Ca(2) and two equivalent Mg(1) atoms. In the fourth O site, O(3) is bonded in a water-like geometry to two equivalent Al(1) atoms. In the fifth O site, O(4) is bonded in a bent 150 degrees geometry to one Ca(1) and one Si(3) atom. In the sixth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Mg(1), and one Si(3) atom. In the seventh O site, O(6) is bonded in a water-like geometry to two equivalent Al(1) atoms. In the eighth O site, O(7) is bonded in a trigonal planar geometry to one Ca(1), one Al(1), and one Si(2) atom. In the ninth O site, O(8) is bonded in a distorted trigonal pyramidal geometry to one Ca(2), two equivalent Al(1), and one Si(2) atom. In the tenth O site, O(9) is bonded in a 3-coordinate geometry to one Ca(2), one Si(2), and one Si(3) atom. In the eleventh O site, O(10) is bonded in a 3-coordinate geometry to two equivalent Al(1) and one Si(1) atom. is represented by the CIF card [CIF]
data_Ca2MgAl2Si3O14
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.364
_cell_length_b   10.364
_cell_length_c   8.843
_cell_angle_alpha   83.162
_cell_angle_beta   83.162
_cell_angle_gamma   33.476
_symmetry_Int_Tables_number   1
_cell_volume   519.812
_cell_formula_units_Z   2
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
  Ca  Ca0  1  0.654  0.654  0.320  1.0
  Ca  Ca1  1  0.346  0.346  0.680  1.0
  Ca  Ca2  1  0.843  0.843  0.253  1.0
  Ca  Ca3  1  0.157  0.157  0.747  1.0
  Mg  Mg4  1  0.500  0.000  0.000  1.0
  Mg  Mg5  1  0.000  0.500  0.000  1.0
  Al  Al6  1  0.740  0.252  0.244  1.0
  Al  Al7  1  0.260  0.748  0.756  1.0
  Al  Al8  1  0.748  0.260  0.756  1.0
  Al  Al9  1  0.252  0.740  0.244  1.0
  Si  Si10  1  0.403  0.403  0.031  1.0
  Si  Si11  1  0.597  0.597  0.969  1.0
  Si  Si12  1  0.913  0.913  0.553  1.0
  Si  Si13  1  0.087  0.087  0.447  1.0
  Si  Si14  1  0.755  0.755  0.658  1.0
  Si  Si15  1  0.245  0.245  0.342  1.0
  O  O16  1  0.635  0.203  0.141  1.0
  O  O17  1  0.365  0.797  0.859  1.0
  O  O18  1  0.797  0.365  0.859  1.0
  O  O19  1  0.203  0.635  0.141  1.0
  O  O20  1  0.673  0.673  0.024  1.0
  O  O21  1  0.327  0.327  0.976  1.0
  O  O22  1  0.972  0.972  0.868  1.0
  O  O23  1  0.028  0.028  0.132  1.0
  O  O24  1  0.694  0.694  0.554  1.0
  O  O25  1  0.306  0.306  0.446  1.0
  O  O26  1  0.480  0.011  0.245  1.0
  O  O27  1  0.520  0.989  0.755  1.0
  O  O28  1  0.989  0.520  0.755  1.0
  O  O29  1  0.011  0.480  0.245  1.0
  O  O30  1  0.458  0.458  0.362  1.0
  O  O31  1  0.542  0.542  0.638  1.0
  O  O32  1  0.294  0.845  0.356  1.0
  O  O33  1  0.706  0.155  0.644  1.0
  O  O34  1  0.155  0.706  0.644  1.0
  O  O35  1  0.845  0.294  0.356  1.0
  O  O36  1  0.946  0.946  0.372  1.0
  O  O37  1  0.054  0.054  0.628  1.0
  O  O38  1  0.830  0.830  0.538  1.0
  O  O39  1  0.170  0.170  0.462  1.0
  O  O40  1  0.543  0.543  0.127  1.0
  O  O41  1  0.457  0.457  0.873  1.0
  O  O42  1  0.814  0.814  0.015  1.0
  O  O43  1  0.186  0.186  0.985  1.0
[/CIF]
.
The compound described by Ca2MgAl2Si3O14 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), two equivalent O(5), and two equivalent O(7) atoms. In the second Ca site, Ca(2) is bonded to one O(11), one O(8), one O(9), two equivalent O(1), and two equivalent O(5) atoms to form distorted CaO7 pentagonal bipyramids that share corners with two equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(3)O4 tetrahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and  an edgeedge with one Si(2)O4 tetrahedra. Mg(1) is bonded to two equivalent O(11), two equivalent O(2), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Ca(2)O7 pentagonal bipyramids. Al(1) is bonded to one O(1), one O(10), one O(3), one O(6), one O(7), and one O(8) atom to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, edges with two equivalent Al(1)O6 octahedra, and  an edgeedge with one Ca(2)O7 pentagonal bipyramid. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(10), one O(2), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Al(1)O6 octahedra, and corners with two equivalent Ca(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 48-55°. In the second Si site, Si(2) is bonded to one O(8), one O(9), and two equivalent O(7) atoms to form SiO4 tetrahedra that share corners with four equivalent Al(1)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  an edgeedge with one Ca(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 51-55°. In the third Si site, Si(3) is bonded to one O(4), one O(9), and two equivalent O(5) atoms to form SiO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with three equivalent Ca(2)O7 pentagonal bipyramids, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 56°. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(2), one Al(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), two equivalent Mg(1), and one Si(1) atom. In the third O site, O(11) is bonded in a trigonal non-coplanar geometry to one Ca(2) and two equivalent Mg(1) atoms. In the fourth O site, O(3) is bonded in a water-like geometry to two equivalent Al(1) atoms. In the fifth O site, O(4) is bonded in a bent 150 degrees geometry to one Ca(1) and one Si(3) atom. In the sixth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Mg(1), and one Si(3) atom. In the seventh O site, O(6) is bonded in a water-like geometry to two equivalent Al(1) atoms. In the eighth O site, O(7) is bonded in a trigonal planar geometry to one Ca(1), one Al(1), and one Si(2) atom. In the ninth O site, O(8) is bonded in a distorted trigonal pyramidal geometry to one Ca(2), two equivalent Al(1), and one Si(2) atom. In the tenth O site, O(9) is bonded in a 3-coordinate geometry to one Ca(2), one Si(2), and one Si(3) atom. In the eleventh O site, O(10) is bonded in a 3-coordinate geometry to two equivalent Al(1) and one Si(1) atom. is represented by the CIF card [CIF]
data_Ca2MgAl2Si3O14
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.364
_cell_length_b   10.364
_cell_length_c   8.843
_cell_angle_alpha   83.162
_cell_angle_beta   83.162
_cell_angle_gamma   33.476
_symmetry_Int_Tables_number   1
_cell_volume   519.812
_cell_formula_units_Z   2
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
  Ca  Ca0  1  0.654  0.654  0.320  1.0
  Ca  Ca1  1  0.346  0.346  0.680  1.0
  Ca  Ca2  1  0.843  0.843  0.253  1.0
  Ca  Ca3  1  0.157  0.157  0.747  1.0
  Mg  Mg4  1  0.500  0.000  0.000  1.0
  Mg  Mg5  1  0.000  0.500  0.000  1.0
  Al  Al6  1  0.740  0.252  0.244  1.0
  Al  Al7  1  0.260  0.748  0.756  1.0
  Al  Al8  1  0.748  0.260  0.756  1.0
  Al  Al9  1  0.252  0.740  0.244  1.0
  Si  Si10  1  0.403  0.403  0.031  1.0
  Si  Si11  1  0.597  0.597  0.969  1.0
  Si  Si12  1  0.913  0.913  0.553  1.0
  Si  Si13  1  0.087  0.087  0.447  1.0
  Si  Si14  1  0.755  0.755  0.658  1.0
  Si  Si15  1  0.245  0.245  0.342  1.0
  O  O16  1  0.635  0.203  0.141  1.0
  O  O17  1  0.365  0.797  0.859  1.0
  O  O18  1  0.797  0.365  0.859  1.0
  O  O19  1  0.203  0.635  0.141  1.0
  O  O20  1  0.673  0.673  0.024  1.0
  O  O21  1  0.327  0.327  0.976  1.0
  O  O22  1  0.972  0.972  0.868  1.0
  O  O23  1  0.028  0.028  0.132  1.0
  O  O24  1  0.694  0.694  0.554  1.0
  O  O25  1  0.306  0.306  0.446  1.0
  O  O26  1  0.480  0.011  0.245  1.0
  O  O27  1  0.520  0.989  0.755  1.0
  O  O28  1  0.989  0.520  0.755  1.0
  O  O29  1  0.011  0.480  0.245  1.0
  O  O30  1  0.458  0.458  0.362  1.0
  O  O31  1  0.542  0.542  0.638  1.0
  O  O32  1  0.294  0.845  0.356  1.0
  O  O33  1  0.706  0.155  0.644  1.0
  O  O34  1  0.155  0.706  0.644  1.0
  O  O35  1  0.845  0.294  0.356  1.0
  O  O36  1  0.946  0.946  0.372  1.0
  O  O37  1  0.054  0.054  0.628  1.0
  O  O38  1  0.830  0.830  0.538  1.0
  O  O39  1  0.170  0.170  0.462  1.0
  O  O40  1  0.543  0.543  0.127  1.0
  O  O41  1  0.457  0.457  0.873  1.0
  O  O42  1  0.814  0.814  0.015  1.0
  O  O43  1  0.186  0.186  0.985  1.0
[/CIF]
.