The compound described by Ca2Al(SiO3)4 crystallizes in the orthorhombic Pmna space group. Ca(1) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Al(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. In the second Si site, Si(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1) and two equivalent Si(2) atoms. In the second O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Ca(1), one Si(1), and one Si(2) atom. In the third O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Al(1), and one Si(1) atom. In the fourth O site, O(3) is bonded in a trigonal non-coplanar geometry to two equivalent Ca(1) and one Al(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2Al(SiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.818
_cell_length_b   5.372
_cell_length_c   18.541
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   479.859
_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  0.000  0.000  0.406  1.0
  Ca  Ca1  1  0.000  0.000  0.594  1.0
  Ca  Ca2  1  0.000  0.500  0.094  1.0
  Ca  Ca3  1  0.000  0.500  0.906  1.0
  Al  Al4  1  0.000  0.000  0.000  1.0
  Al  Al5  1  0.000  0.500  0.500  1.0
  Si  Si6  1  0.500  0.000  0.119  1.0
  Si  Si7  1  0.500  0.000  0.881  1.0
  Si  Si8  1  0.500  0.500  0.381  1.0
  Si  Si9  1  0.500  0.500  0.619  1.0
  Si  Si10  1  0.190  0.250  0.250  1.0
  Si  Si11  1  0.810  0.750  0.750  1.0
  Si  Si12  1  0.810  0.750  0.250  1.0
  Si  Si13  1  0.190  0.250  0.750  1.0
  O  O14  1  0.367  0.219  0.176  1.0
  O  O15  1  0.633  0.781  0.824  1.0
  O  O16  1  0.633  0.719  0.324  1.0
  O  O17  1  0.367  0.281  0.324  1.0
  O  O18  1  0.367  0.281  0.676  1.0
  O  O19  1  0.633  0.719  0.676  1.0
  O  O20  1  0.633  0.781  0.176  1.0
  O  O21  1  0.367  0.219  0.824  1.0
  O  O22  1  0.754  0.130  0.078  1.0
  O  O23  1  0.246  0.870  0.922  1.0
  O  O24  1  0.246  0.630  0.422  1.0
  O  O25  1  0.754  0.370  0.422  1.0
  O  O26  1  0.754  0.370  0.578  1.0
  O  O27  1  0.246  0.630  0.578  1.0
  O  O28  1  0.246  0.870  0.078  1.0
  O  O29  1  0.754  0.130  0.922  1.0
  O  O30  1  0.179  0.304  0.000  1.0
  O  O31  1  0.821  0.696  0.000  1.0
  O  O32  1  0.821  0.804  0.500  1.0
  O  O33  1  0.179  0.196  0.500  1.0
  O  O34  1  0.000  0.000  0.266  1.0
  O  O35  1  0.000  0.000  0.734  1.0
  O  O36  1  0.000  0.500  0.234  1.0
  O  O37  1  0.000  0.500  0.766  1.0
[/CIF]
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The compound described by Ca2Al(SiO3)4 crystallizes in the orthorhombic Pmna space group. Ca(1) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Al(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. In the second Si site, Si(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1) and two equivalent Si(2) atoms. In the second O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Ca(1), one Si(1), and one Si(2) atom. In the third O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Al(1), and one Si(1) atom. In the fourth O site, O(3) is bonded in a trigonal non-coplanar geometry to two equivalent Ca(1) and one Al(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2Al(SiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.818
_cell_length_b   5.372
_cell_length_c   18.541
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   479.859
_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  0.000  0.000  0.406  1.0
  Ca  Ca1  1  0.000  0.000  0.594  1.0
  Ca  Ca2  1  0.000  0.500  0.094  1.0
  Ca  Ca3  1  0.000  0.500  0.906  1.0
  Al  Al4  1  0.000  0.000  0.000  1.0
  Al  Al5  1  0.000  0.500  0.500  1.0
  Si  Si6  1  0.500  0.000  0.119  1.0
  Si  Si7  1  0.500  0.000  0.881  1.0
  Si  Si8  1  0.500  0.500  0.381  1.0
  Si  Si9  1  0.500  0.500  0.619  1.0
  Si  Si10  1  0.190  0.250  0.250  1.0
  Si  Si11  1  0.810  0.750  0.750  1.0
  Si  Si12  1  0.810  0.750  0.250  1.0
  Si  Si13  1  0.190  0.250  0.750  1.0
  O  O14  1  0.367  0.219  0.176  1.0
  O  O15  1  0.633  0.781  0.824  1.0
  O  O16  1  0.633  0.719  0.324  1.0
  O  O17  1  0.367  0.281  0.324  1.0
  O  O18  1  0.367  0.281  0.676  1.0
  O  O19  1  0.633  0.719  0.676  1.0
  O  O20  1  0.633  0.781  0.176  1.0
  O  O21  1  0.367  0.219  0.824  1.0
  O  O22  1  0.754  0.130  0.078  1.0
  O  O23  1  0.246  0.870  0.922  1.0
  O  O24  1  0.246  0.630  0.422  1.0
  O  O25  1  0.754  0.370  0.422  1.0
  O  O26  1  0.754  0.370  0.578  1.0
  O  O27  1  0.246  0.630  0.578  1.0
  O  O28  1  0.246  0.870  0.078  1.0
  O  O29  1  0.754  0.130  0.922  1.0
  O  O30  1  0.179  0.304  0.000  1.0
  O  O31  1  0.821  0.696  0.000  1.0
  O  O32  1  0.821  0.804  0.500  1.0
  O  O33  1  0.179  0.196  0.500  1.0
  O  O34  1  0.000  0.000  0.266  1.0
  O  O35  1  0.000  0.000  0.734  1.0
  O  O36  1  0.000  0.500  0.234  1.0
  O  O37  1  0.000  0.500  0.766  1.0
[/CIF]
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