The structure described by Na2CaMn3(SiO3)6 is Esseneite-derived structured and crystallizes in the triclinic P1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(14), one O(3), one O(5), one O(6), one O(7), and one O(8) atom. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(13), one O(2), one O(4), one O(6), one O(7), one O(8), and one O(9) atom. Ca(1) is bonded in a 6-coordinate geometry to one O(12), one O(15), one O(16), one O(17), one O(4), and one O(9) atom. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 6-coordinate geometry to one O(11), one O(14), one O(16), one O(17), one O(18), and one O(3) atom. In the second Mn site, Mn(2) is bonded to one O(12), one O(13), one O(15), one O(17), one O(18), and one O(4) atom to form distorted MnO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and  an edgeedge with one Mn(3)O6 octahedra. In the third Mn site, Mn(3) is bonded to one O(10), one O(11), one O(15), one O(16), one O(18), and one O(3) atom to form distorted MnO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Mn(2)O6 octahedra. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(16), one O(5), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(3)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. In the second Si site, Si(2) is bonded to one O(10), one O(15), one O(2), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra, corners with two equivalent Mn(3)O6 octahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 28-68°. In the third Si site, Si(3) is bonded to one O(1), one O(13), one O(18), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(3)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 28-60°. In the fourth Si site, Si(4) is bonded to one O(14), one O(17), one O(2), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 60°. In the fifth Si site, Si(5) is bonded to one O(11), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-51°. In the sixth Si site, Si(6) is bonded to one O(12), one O(3), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-58°. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Si(1), and one Si(3) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Na(2), one Si(2), and one Si(4) atom. In the third O site, O(3) is bonded to one Na(1), one Mn(1), one Mn(3), and one Si(6) atom to form distorted corner-sharing ONaMn2Si trigonal pyramids. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(2), one Ca(1), one Mn(2), and one Si(5) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Na(1), one Si(1), and one Si(5) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Na(1), one Na(2), one Si(2), and one Si(6) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Si(3), and one Si(5) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Na(1), one Na(2), one Si(4), and one Si(6) atom. In the ninth O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Na(2), one Ca(1), and one Si(1) atom. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one Na(1), one Mn(3), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(3), and one Si(5) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Ca(1), one Mn(2), and one Si(6) atom. In the thirteenth O site, O(13) is bonded in a distorted T-shaped geometry to one Na(2), one Mn(2), and one Si(3) atom. In the fourteenth O site, O(14) is bonded in a distorted T-shaped geometry to one Na(1), one Mn(1), and one Si(4) atom. In the fifteenth O site, O(15) is bonded in a 4-coordinate geometry to one Ca(1), one Mn(2), one Mn(3), and one Si(2) atom. In the sixteenth O site, O(16) is bonded in a 4-coordinate geometry to one Ca(1), one Mn(1), one Mn(3), and one Si(1) atom. In the seventeenth O site, O(17) is bonded to one Ca(1), one Mn(1), one Mn(2), and one Si(4) atom to form distorted corner-sharing OCaMn2Si tetrahedra. In the eighteenth O site, O(18) is bonded in a 4-coordinate geometry to one Mn(1), one Mn(2), one Mn(3), and one Si(3) atom. is represented by the CIF file [CIF]
data_Na2CaMn3(SiO3)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.625
_cell_length_b   7.205
_cell_length_c   7.590
_cell_angle_alpha   100.850
_cell_angle_beta   94.019
_cell_angle_gamma   89.279
_symmetry_Int_Tables_number   1
_cell_volume   354.896
_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
  Na  Na0  1  0.129  0.235  0.920  1.0
  Na  Na1  1  0.868  0.754  0.081  1.0
  Ca  Ca2  1  0.647  0.092  0.350  1.0
  Mn  Mn3  1  0.362  0.423  0.652  1.0
  Mn  Mn4  1  0.627  0.578  0.351  1.0
  Mn  Mn5  1  0.351  0.922  0.647  1.0
  Si  Si6  1  0.161  0.092  0.287  1.0
  Si  Si7  1  0.847  0.904  0.725  1.0
  Si  Si8  1  0.140  0.535  0.289  1.0
  Si  Si9  1  0.856  0.471  0.705  1.0
  Si  Si10  1  0.353  0.757  0.044  1.0
  Si  Si11  1  0.645  0.244  0.951  1.0
  O  O12  1  0.145  0.304  0.234  1.0
  O  O13  1  0.872  0.698  0.781  1.0
  O  O14  1  0.442  0.213  0.815  1.0
  O  O15  1  0.559  0.746  0.177  1.0
  O  O16  1  0.266  0.974  0.102  1.0
  O  O17  1  0.783  0.045  0.914  1.0
  O  O18  1  0.188  0.605  0.096  1.0
  O  O19  1  0.790  0.402  0.889  1.0
  O  O20  1  0.949  0.002  0.300  1.0
  O  O21  1  0.069  0.970  0.685  1.0
  O  O22  1  0.382  0.721  0.827  1.0
  O  O23  1  0.610  0.309  0.162  1.0
  O  O24  1  0.919  0.610  0.346  1.0
  O  O25  1  0.065  0.377  0.649  1.0
  O  O26  1  0.647  0.895  0.580  1.0
  O  O27  1  0.330  0.094  0.458  1.0
  O  O28  1  0.663  0.424  0.549  1.0
  O  O29  1  0.335  0.606  0.435  1.0
[/CIF]
.
The structure described by Na2CaMn3(SiO3)6 is Esseneite-derived structured and crystallizes in the triclinic P1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(14), one O(3), one O(5), one O(6), one O(7), and one O(8) atom. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(13), one O(2), one O(4), one O(6), one O(7), one O(8), and one O(9) atom. Ca(1) is bonded in a 6-coordinate geometry to one O(12), one O(15), one O(16), one O(17), one O(4), and one O(9) atom. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 6-coordinate geometry to one O(11), one O(14), one O(16), one O(17), one O(18), and one O(3) atom. In the second Mn site, Mn(2) is bonded to one O(12), one O(13), one O(15), one O(17), one O(18), and one O(4) atom to form distorted MnO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and  an edgeedge with one Mn(3)O6 octahedra. In the third Mn site, Mn(3) is bonded to one O(10), one O(11), one O(15), one O(16), one O(18), and one O(3) atom to form distorted MnO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Mn(2)O6 octahedra. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(16), one O(5), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(3)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. In the second Si site, Si(2) is bonded to one O(10), one O(15), one O(2), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra, corners with two equivalent Mn(3)O6 octahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 28-68°. In the third Si site, Si(3) is bonded to one O(1), one O(13), one O(18), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(3)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 28-60°. In the fourth Si site, Si(4) is bonded to one O(14), one O(17), one O(2), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 60°. In the fifth Si site, Si(5) is bonded to one O(11), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-51°. In the sixth Si site, Si(6) is bonded to one O(12), one O(3), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-58°. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Si(1), and one Si(3) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Na(2), one Si(2), and one Si(4) atom. In the third O site, O(3) is bonded to one Na(1), one Mn(1), one Mn(3), and one Si(6) atom to form distorted corner-sharing ONaMn2Si trigonal pyramids. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(2), one Ca(1), one Mn(2), and one Si(5) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Na(1), one Si(1), and one Si(5) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Na(1), one Na(2), one Si(2), and one Si(6) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Si(3), and one Si(5) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Na(1), one Na(2), one Si(4), and one Si(6) atom. In the ninth O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Na(2), one Ca(1), and one Si(1) atom. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one Na(1), one Mn(3), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(3), and one Si(5) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Ca(1), one Mn(2), and one Si(6) atom. In the thirteenth O site, O(13) is bonded in a distorted T-shaped geometry to one Na(2), one Mn(2), and one Si(3) atom. In the fourteenth O site, O(14) is bonded in a distorted T-shaped geometry to one Na(1), one Mn(1), and one Si(4) atom. In the fifteenth O site, O(15) is bonded in a 4-coordinate geometry to one Ca(1), one Mn(2), one Mn(3), and one Si(2) atom. In the sixteenth O site, O(16) is bonded in a 4-coordinate geometry to one Ca(1), one Mn(1), one Mn(3), and one Si(1) atom. In the seventeenth O site, O(17) is bonded to one Ca(1), one Mn(1), one Mn(2), and one Si(4) atom to form distorted corner-sharing OCaMn2Si tetrahedra. In the eighteenth O site, O(18) is bonded in a 4-coordinate geometry to one Mn(1), one Mn(2), one Mn(3), and one Si(3) atom. is represented by the CIF file [CIF]
data_Na2CaMn3(SiO3)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.625
_cell_length_b   7.205
_cell_length_c   7.590
_cell_angle_alpha   100.850
_cell_angle_beta   94.019
_cell_angle_gamma   89.279
_symmetry_Int_Tables_number   1
_cell_volume   354.896
_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
  Na  Na0  1  0.129  0.235  0.920  1.0
  Na  Na1  1  0.868  0.754  0.081  1.0
  Ca  Ca2  1  0.647  0.092  0.350  1.0
  Mn  Mn3  1  0.362  0.423  0.652  1.0
  Mn  Mn4  1  0.627  0.578  0.351  1.0
  Mn  Mn5  1  0.351  0.922  0.647  1.0
  Si  Si6  1  0.161  0.092  0.287  1.0
  Si  Si7  1  0.847  0.904  0.725  1.0
  Si  Si8  1  0.140  0.535  0.289  1.0
  Si  Si9  1  0.856  0.471  0.705  1.0
  Si  Si10  1  0.353  0.757  0.044  1.0
  Si  Si11  1  0.645  0.244  0.951  1.0
  O  O12  1  0.145  0.304  0.234  1.0
  O  O13  1  0.872  0.698  0.781  1.0
  O  O14  1  0.442  0.213  0.815  1.0
  O  O15  1  0.559  0.746  0.177  1.0
  O  O16  1  0.266  0.974  0.102  1.0
  O  O17  1  0.783  0.045  0.914  1.0
  O  O18  1  0.188  0.605  0.096  1.0
  O  O19  1  0.790  0.402  0.889  1.0
  O  O20  1  0.949  0.002  0.300  1.0
  O  O21  1  0.069  0.970  0.685  1.0
  O  O22  1  0.382  0.721  0.827  1.0
  O  O23  1  0.610  0.309  0.162  1.0
  O  O24  1  0.919  0.610  0.346  1.0
  O  O25  1  0.065  0.377  0.649  1.0
  O  O26  1  0.647  0.895  0.580  1.0
  O  O27  1  0.330  0.094  0.458  1.0
  O  O28  1  0.663  0.424  0.549  1.0
  O  O29  1  0.335  0.606  0.435  1.0
[/CIF]
.