The material described by CaNaAlSi2O7 crystallizes in the tetragonal P-42_1m space group. Na(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(4), and two equivalent O(5) atoms. Ca(1) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(2), and two equivalent O(3) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent O(2) atoms to form AlO4 tetrahedra that share corners with four equivalent Si(2)O4 tetrahedra. In the second Al site, Al(2) is bonded to four equivalent O(5) atoms to form AlO4 tetrahedra 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 one O(3), one O(6), and two equivalent O(5) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with two equivalent Al(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra and corners with two equivalent Al(1)O4 tetrahedra. There are six inequivalent O sites. In the first O site, O(6) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent Si(2) atoms. In the third O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ca(1), one Al(1), and one Si(2) atom. In the fourth O site, O(3) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Ca(1), and one Si(1) atom. In the fifth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Ca(1), and one Si(2) atom. In the sixth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Al(2), and one Si(1) atom. is represented by the CIF card [CIF]
data_NaCaAlSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.720
_cell_length_b   7.759
_cell_length_c   7.759
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   765.689
_cell_formula_units_Z   4
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
  Na  Na0  1  0.313  0.133  0.633  1.0
  Na  Na1  1  0.313  0.867  0.367  1.0
  Na  Na2  1  0.687  0.633  0.867  1.0
  Na  Na3  1  0.687  0.367  0.133  1.0
  Ca  Ca4  1  0.212  0.346  0.154  1.0
  Ca  Ca5  1  0.212  0.654  0.846  1.0
  Ca  Ca6  1  0.788  0.154  0.654  1.0
  Ca  Ca7  1  0.788  0.846  0.346  1.0
  Al  Al8  1  0.000  0.000  0.000  1.0
  Al  Al9  1  0.000  0.500  0.500  1.0
  Al  Al10  1  0.500  0.000  0.000  1.0
  Al  Al11  1  0.500  0.500  0.500  1.0
  Si  Si12  1  0.607  0.139  0.361  1.0
  Si  Si13  1  0.607  0.861  0.639  1.0
  Si  Si14  1  0.893  0.364  0.864  1.0
  Si  Si15  1  0.893  0.636  0.136  1.0
  Si  Si16  1  0.107  0.136  0.364  1.0
  Si  Si17  1  0.107  0.864  0.636  1.0
  Si  Si18  1  0.393  0.361  0.861  1.0
  Si  Si19  1  0.393  0.639  0.139  1.0
  O  O20  1  0.049  0.000  0.500  1.0
  O  O21  1  0.075  0.898  0.838  1.0
  O  O22  1  0.075  0.662  0.602  1.0
  O  O23  1  0.075  0.102  0.162  1.0
  O  O24  1  0.075  0.338  0.398  1.0
  O  O25  1  0.264  0.374  0.874  1.0
  O  O26  1  0.264  0.626  0.126  1.0
  O  O27  1  0.235  0.135  0.365  1.0
  O  O28  1  0.235  0.865  0.635  1.0
  O  O29  1  0.424  0.836  0.093  1.0
  O  O30  1  0.424  0.593  0.336  1.0
  O  O31  1  0.424  0.407  0.664  1.0
  O  O32  1  0.424  0.164  0.907  1.0
  O  O33  1  0.447  0.500  0.000  1.0
  O  O34  1  0.553  0.000  0.500  1.0
  O  O35  1  0.576  0.907  0.836  1.0
  O  O36  1  0.576  0.664  0.593  1.0
  O  O37  1  0.576  0.093  0.164  1.0
  O  O38  1  0.576  0.336  0.407  1.0
  O  O39  1  0.765  0.365  0.865  1.0
  O  O40  1  0.765  0.635  0.135  1.0
  O  O41  1  0.736  0.126  0.374  1.0
  O  O42  1  0.736  0.874  0.626  1.0
  O  O43  1  0.925  0.838  0.102  1.0
  O  O44  1  0.925  0.602  0.338  1.0
  O  O45  1  0.925  0.398  0.662  1.0
  O  O46  1  0.925  0.162  0.898  1.0
  O  O47  1  0.951  0.500  0.000  1.0
[/CIF]
.
The material described by CaNaAlSi2O7 crystallizes in the tetragonal P-42_1m space group. Na(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(4), and two equivalent O(5) atoms. Ca(1) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(2), and two equivalent O(3) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent O(2) atoms to form AlO4 tetrahedra that share corners with four equivalent Si(2)O4 tetrahedra. In the second Al site, Al(2) is bonded to four equivalent O(5) atoms to form AlO4 tetrahedra 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 one O(3), one O(6), and two equivalent O(5) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with two equivalent Al(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra and corners with two equivalent Al(1)O4 tetrahedra. There are six inequivalent O sites. In the first O site, O(6) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent Si(2) atoms. In the third O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ca(1), one Al(1), and one Si(2) atom. In the fourth O site, O(3) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Ca(1), and one Si(1) atom. In the fifth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Ca(1), and one Si(2) atom. In the sixth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Al(2), and one Si(1) atom. is represented by the CIF card [CIF]
data_NaCaAlSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.720
_cell_length_b   7.759
_cell_length_c   7.759
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   765.689
_cell_formula_units_Z   4
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
  Na  Na0  1  0.313  0.133  0.633  1.0
  Na  Na1  1  0.313  0.867  0.367  1.0
  Na  Na2  1  0.687  0.633  0.867  1.0
  Na  Na3  1  0.687  0.367  0.133  1.0
  Ca  Ca4  1  0.212  0.346  0.154  1.0
  Ca  Ca5  1  0.212  0.654  0.846  1.0
  Ca  Ca6  1  0.788  0.154  0.654  1.0
  Ca  Ca7  1  0.788  0.846  0.346  1.0
  Al  Al8  1  0.000  0.000  0.000  1.0
  Al  Al9  1  0.000  0.500  0.500  1.0
  Al  Al10  1  0.500  0.000  0.000  1.0
  Al  Al11  1  0.500  0.500  0.500  1.0
  Si  Si12  1  0.607  0.139  0.361  1.0
  Si  Si13  1  0.607  0.861  0.639  1.0
  Si  Si14  1  0.893  0.364  0.864  1.0
  Si  Si15  1  0.893  0.636  0.136  1.0
  Si  Si16  1  0.107  0.136  0.364  1.0
  Si  Si17  1  0.107  0.864  0.636  1.0
  Si  Si18  1  0.393  0.361  0.861  1.0
  Si  Si19  1  0.393  0.639  0.139  1.0
  O  O20  1  0.049  0.000  0.500  1.0
  O  O21  1  0.075  0.898  0.838  1.0
  O  O22  1  0.075  0.662  0.602  1.0
  O  O23  1  0.075  0.102  0.162  1.0
  O  O24  1  0.075  0.338  0.398  1.0
  O  O25  1  0.264  0.374  0.874  1.0
  O  O26  1  0.264  0.626  0.126  1.0
  O  O27  1  0.235  0.135  0.365  1.0
  O  O28  1  0.235  0.865  0.635  1.0
  O  O29  1  0.424  0.836  0.093  1.0
  O  O30  1  0.424  0.593  0.336  1.0
  O  O31  1  0.424  0.407  0.664  1.0
  O  O32  1  0.424  0.164  0.907  1.0
  O  O33  1  0.447  0.500  0.000  1.0
  O  O34  1  0.553  0.000  0.500  1.0
  O  O35  1  0.576  0.907  0.836  1.0
  O  O36  1  0.576  0.664  0.593  1.0
  O  O37  1  0.576  0.093  0.164  1.0
  O  O38  1  0.576  0.336  0.407  1.0
  O  O39  1  0.765  0.365  0.865  1.0
  O  O40  1  0.765  0.635  0.135  1.0
  O  O41  1  0.736  0.126  0.374  1.0
  O  O42  1  0.736  0.874  0.626  1.0
  O  O43  1  0.925  0.838  0.102  1.0
  O  O44  1  0.925  0.602  0.338  1.0
  O  O45  1  0.925  0.398  0.662  1.0
  O  O46  1  0.925  0.162  0.898  1.0
  O  O47  1  0.951  0.500  0.000  1.0
[/CIF]
.