The compound described by NaCaGaSi2O7 crystallizes in the orthorhombic P2_12_12_1 space group. Na(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(4), one O(6), two equivalent O(5), and two equivalent O(7) atoms. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(4), one O(7), two equivalent O(3), and two equivalent O(6) atoms. Ga(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form GaO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra and corners with two equivalent Ga(1)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with two equivalent Ga(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), one Ca(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Ca(1), one Ga(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Ga(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(1), one Ca(1), one Ga(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Ga(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Ca(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Ca(1), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaCaGaSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.238
_cell_length_b   7.786
_cell_length_c   7.794
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   621.295
_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  0.245  0.669  0.836  1.0
  Na  Na1  1  0.255  0.831  0.336  1.0
  Na  Na2  1  0.745  0.331  0.164  1.0
  Na  Na3  1  0.755  0.169  0.664  1.0
  Ca  Ca4  1  0.241  0.348  0.160  1.0
  Ca  Ca5  1  0.259  0.152  0.660  1.0
  Ca  Ca6  1  0.741  0.652  0.840  1.0
  Ca  Ca7  1  0.759  0.848  0.340  1.0
  Ga  Ga8  1  0.000  0.003  1.000  1.0
  Ga  Ga9  1  1.000  0.503  0.500  1.0
  Ga  Ga10  1  0.500  0.997  0.000  1.0
  Ga  Ga11  1  0.500  0.497  0.500  1.0
  Si  Si12  1  0.025  0.137  0.359  1.0
  Si  Si13  1  0.027  0.854  0.642  1.0
  Si  Si14  1  0.475  0.363  0.859  1.0
  Si  Si15  1  0.473  0.646  0.142  1.0
  Si  Si16  1  0.527  0.146  0.358  1.0
  Si  Si17  1  0.525  0.863  0.641  1.0
  Si  Si18  1  0.973  0.354  0.858  1.0
  Si  Si19  1  0.975  0.637  0.141  1.0
  O  O20  1  0.086  0.001  0.504  1.0
  O  O21  1  0.099  0.917  0.821  1.0
  O  O22  1  0.097  0.320  0.414  1.0
  O  O23  1  0.102  0.091  0.177  1.0
  O  O24  1  0.103  0.676  0.587  1.0
  O  O25  1  0.130  0.340  0.858  1.0
  O  O26  1  0.131  0.626  0.149  1.0
  O  O27  1  0.370  0.160  0.358  1.0
  O  O28  1  0.369  0.874  0.649  1.0
  O  O29  1  0.403  0.180  0.914  1.0
  O  O30  1  0.398  0.409  0.677  1.0
  O  O31  1  0.401  0.583  0.321  1.0
  O  O32  1  0.397  0.824  0.087  1.0
  O  O33  1  0.414  0.499  0.004  1.0
  O  O34  1  0.586  0.999  0.496  1.0
  O  O35  1  0.599  0.083  0.179  1.0
  O  O36  1  0.603  0.324  0.413  1.0
  O  O37  1  0.602  0.909  0.823  1.0
  O  O38  1  0.597  0.680  0.586  1.0
  O  O39  1  0.631  0.374  0.851  1.0
  O  O40  1  0.630  0.660  0.142  1.0
  O  O41  1  0.869  0.126  0.351  1.0
  O  O42  1  0.870  0.840  0.642  1.0
  O  O43  1  0.897  0.176  0.913  1.0
  O  O44  1  0.901  0.417  0.679  1.0
  O  O45  1  0.898  0.591  0.323  1.0
  O  O46  1  0.903  0.820  0.086  1.0
  O  O47  1  0.914  0.501  0.996  1.0
[/CIF]
.
The compound described by NaCaGaSi2O7 crystallizes in the orthorhombic P2_12_12_1 space group. Na(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(4), one O(6), two equivalent O(5), and two equivalent O(7) atoms. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(4), one O(7), two equivalent O(3), and two equivalent O(6) atoms. Ga(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form GaO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra and corners with two equivalent Ga(1)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with two equivalent Ga(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), one Ca(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Ca(1), one Ga(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Ga(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(1), one Ca(1), one Ga(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Ga(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Ca(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Ca(1), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaCaGaSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.238
_cell_length_b   7.786
_cell_length_c   7.794
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   621.295
_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  0.245  0.669  0.836  1.0
  Na  Na1  1  0.255  0.831  0.336  1.0
  Na  Na2  1  0.745  0.331  0.164  1.0
  Na  Na3  1  0.755  0.169  0.664  1.0
  Ca  Ca4  1  0.241  0.348  0.160  1.0
  Ca  Ca5  1  0.259  0.152  0.660  1.0
  Ca  Ca6  1  0.741  0.652  0.840  1.0
  Ca  Ca7  1  0.759  0.848  0.340  1.0
  Ga  Ga8  1  0.000  0.003  1.000  1.0
  Ga  Ga9  1  1.000  0.503  0.500  1.0
  Ga  Ga10  1  0.500  0.997  0.000  1.0
  Ga  Ga11  1  0.500  0.497  0.500  1.0
  Si  Si12  1  0.025  0.137  0.359  1.0
  Si  Si13  1  0.027  0.854  0.642  1.0
  Si  Si14  1  0.475  0.363  0.859  1.0
  Si  Si15  1  0.473  0.646  0.142  1.0
  Si  Si16  1  0.527  0.146  0.358  1.0
  Si  Si17  1  0.525  0.863  0.641  1.0
  Si  Si18  1  0.973  0.354  0.858  1.0
  Si  Si19  1  0.975  0.637  0.141  1.0
  O  O20  1  0.086  0.001  0.504  1.0
  O  O21  1  0.099  0.917  0.821  1.0
  O  O22  1  0.097  0.320  0.414  1.0
  O  O23  1  0.102  0.091  0.177  1.0
  O  O24  1  0.103  0.676  0.587  1.0
  O  O25  1  0.130  0.340  0.858  1.0
  O  O26  1  0.131  0.626  0.149  1.0
  O  O27  1  0.370  0.160  0.358  1.0
  O  O28  1  0.369  0.874  0.649  1.0
  O  O29  1  0.403  0.180  0.914  1.0
  O  O30  1  0.398  0.409  0.677  1.0
  O  O31  1  0.401  0.583  0.321  1.0
  O  O32  1  0.397  0.824  0.087  1.0
  O  O33  1  0.414  0.499  0.004  1.0
  O  O34  1  0.586  0.999  0.496  1.0
  O  O35  1  0.599  0.083  0.179  1.0
  O  O36  1  0.603  0.324  0.413  1.0
  O  O37  1  0.602  0.909  0.823  1.0
  O  O38  1  0.597  0.680  0.586  1.0
  O  O39  1  0.631  0.374  0.851  1.0
  O  O40  1  0.630  0.660  0.142  1.0
  O  O41  1  0.869  0.126  0.351  1.0
  O  O42  1  0.870  0.840  0.642  1.0
  O  O43  1  0.897  0.176  0.913  1.0
  O  O44  1  0.901  0.417  0.679  1.0
  O  O45  1  0.898  0.591  0.323  1.0
  O  O46  1  0.903  0.820  0.086  1.0
  O  O47  1  0.914  0.501  0.996  1.0
[/CIF]
.