The material described by K8Mg(SiO3)8 crystallizes in the triclinic P1 space group. There are eight inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one O(14), one O(17), one O(19), one O(24), one O(6), and one O(9) atom. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(10), one O(13), one O(18), one O(21), one O(23), and one O(5) atom. In the third K site, K(3) is bonded in a 6-coordinate geometry to one O(11), one O(15), one O(17), one O(19), one O(22), and one O(8) atom. In the fourth K site, K(4) is bonded in a 5-coordinate geometry to one O(16), one O(20), one O(21), one O(23), and one O(7) atom. In the fifth K site, K(5) is bonded in a 6-coordinate geometry to one O(14), one O(15), one O(17), one O(2), one O(23), and one O(4) atom. In the sixth K site, K(6) is bonded in a 5-coordinate geometry to one O(13), one O(16), one O(24), one O(3), and one O(6) atom. In the seventh K site, K(7) is bonded in a 6-coordinate geometry to one O(13), one O(16), one O(19), one O(2), one O(21), and one O(4) atom. In the eighth K site, K(8) is bonded in a 5-coordinate geometry to one O(1), one O(12), one O(14), one O(15), and one O(20) atom. Mg(1) is bonded to one O(1), one O(18), one O(22), and one O(3) atom to form MgO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  an edgeedge with one Si(6)O4 tetrahedra. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(13), one O(5), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(7)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(10), one O(14), one O(2), and one O(6) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(11), one O(15), one O(3), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(7)O4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(12), one O(16), one O(4), and one O(8) atom to form corner-sharing SiO4 tetrahedra. In the fifth Si site, Si(5) is bonded to one O(11), one O(17), one O(21), and one O(5) atom to form corner-sharing SiO4 tetrahedra. In the sixth Si site, Si(6) is bonded to one O(12), one O(18), one O(22), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. In the seventh Si site, Si(7) is bonded to one O(19), one O(23), one O(7), and one O(9) atom to form corner-sharing SiO4 tetrahedra. In the eighth Si site, Si(8) is bonded to one O(10), one O(20), one O(24), and one O(8) atom to form corner-sharing SiO4 tetrahedra. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(8), one Mg(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(5), one K(7), and one Si(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one K(6), one Mg(1), and one Si(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one K(5), one K(7), and one Si(4) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one K(2), one Si(1), and one Si(5) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one K(1), one K(6), one Si(2), and one Si(6) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one K(4), one Si(3), and one Si(7) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one K(3), one Si(4), and one Si(8) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one K(1), one Si(1), and one Si(7) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to one K(2), one Si(2), and one Si(8) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one K(3), one Si(3), and one Si(5) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one K(8), one Si(4), and one Si(6) atom. In the thirteenth O site, O(13) is bonded in a distorted single-bond geometry to one K(2), one K(6), one K(7), and one Si(1) atom. In the fourteenth O site, O(14) is bonded in a distorted single-bond geometry to one K(1), one K(5), one K(8), and one Si(2) atom. In the fifteenth O site, O(15) is bonded in a distorted single-bond geometry to one K(3), one K(5), one K(8), and one Si(3) atom. In the sixteenth O site, O(16) is bonded in a distorted single-bond geometry to one K(4), one K(6), one K(7), and one Si(4) atom. In the seventeenth O site, O(17) is bonded in a distorted single-bond geometry to one K(1), one K(3), one K(5), and one Si(5) atom. In the eighteenth O site, O(18) is bonded in a 3-coordinate geometry to one K(2), one Mg(1), and one Si(6) atom. In the nineteenth O site, O(19) is bonded in a distorted single-bond geometry to one K(1), one K(3), one K(7), and one Si(7) atom. In the twentieth O site, O(20) is bonded in a 3-coordinate geometry to one K(4), one K(8), and one Si(8) atom. In the twenty-first O site, O(21) is bonded in a distorted single-bond geometry to one K(2), one K(4), one K(7), and one Si(5) atom. In the twenty-second O site, O(22) is bonded in a 3-coordinate geometry to one K(3), one Mg(1), and one Si(6) atom. In the twenty-third O site, O(23) is bonded in a distorted single-bond geometry to one K(2), one K(4), one K(5), and one Si(7) atom. In the twenty-fourth O site, O(24) is bonded in a 3-coordinate geometry to one K(1), one K(6), and one Si(8) atom. is represented by the CIF file [CIF]
data_K8Mg(SiO3)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.279
_cell_length_b   8.265
_cell_length_c   10.276
_cell_angle_alpha   88.787
_cell_angle_beta   88.930
_cell_angle_gamma   96.332
_symmetry_Int_Tables_number   1
_cell_volume   698.585
_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
  K  K0  1  0.992  0.022  0.735  1.0
  K  K1  1  0.492  0.537  0.740  1.0
  K  K2  1  0.968  0.010  0.262  1.0
  K  K3  1  0.479  0.505  0.263  1.0
  K  K4  1  0.677  0.195  0.516  1.0
  K  K5  1  0.172  0.778  0.984  1.0
  K  K6  1  0.305  0.822  0.484  1.0
  K  K7  1  0.727  0.324  0.016  1.0
  Mg  Mg8  1  0.108  0.394  0.001  1.0
  Si  Si9  1  0.026  0.516  0.708  1.0
  Si  Si10  1  0.513  0.007  0.807  1.0
  Si  Si11  1  0.986  0.473  0.292  1.0
  Si  Si12  1  0.494  0.985  0.193  1.0
  Si  Si13  1  0.820  0.681  0.500  1.0
  Si  Si14  1  0.312  0.188  0.997  1.0
  Si  Si15  1  0.192  0.308  0.501  1.0
  Si  Si16  1  0.689  0.810  0.002  1.0
  O  O17  1  0.977  0.448  0.855  1.0
  O  O18  1  0.486  0.963  0.657  1.0
  O  O19  1  0.052  0.525  0.146  1.0
  O  O20  1  0.524  0.025  0.344  1.0
  O  O21  1  0.866  0.573  0.630  1.0
  O  O22  1  0.346  0.065  0.875  1.0
  O  O23  1  0.145  0.416  0.373  1.0
  O  O24  1  0.664  0.941  0.120  1.0
  O  O25  1  0.079  0.358  0.625  1.0
  O  O26  1  0.549  0.842  0.893  1.0
  O  O27  1  0.933  0.633  0.374  1.0
  O  O28  1  0.442  0.146  0.111  1.0
  O  O29  1  0.171  0.663  0.714  1.0
  O  O30  1  0.666  0.146  0.793  1.0
  O  O31  1  0.838  0.329  0.286  1.0
  O  O32  1  0.353  0.832  0.207  1.0
  O  O33  1  0.850  0.877  0.517  1.0
  O  O34  1  0.345  0.381  0.959  1.0
  O  O35  1  0.159  0.112  0.483  1.0
  O  O36  1  0.662  0.621  0.047  1.0
  O  O37  1  0.625  0.648  0.479  1.0
  O  O38  1  0.122  0.155  0.041  1.0
  O  O39  1  0.386  0.342  0.523  1.0
  O  O40  1  0.874  0.839  0.949  1.0
[/CIF]
.
The material described by K8Mg(SiO3)8 crystallizes in the triclinic P1 space group. There are eight inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one O(14), one O(17), one O(19), one O(24), one O(6), and one O(9) atom. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(10), one O(13), one O(18), one O(21), one O(23), and one O(5) atom. In the third K site, K(3) is bonded in a 6-coordinate geometry to one O(11), one O(15), one O(17), one O(19), one O(22), and one O(8) atom. In the fourth K site, K(4) is bonded in a 5-coordinate geometry to one O(16), one O(20), one O(21), one O(23), and one O(7) atom. In the fifth K site, K(5) is bonded in a 6-coordinate geometry to one O(14), one O(15), one O(17), one O(2), one O(23), and one O(4) atom. In the sixth K site, K(6) is bonded in a 5-coordinate geometry to one O(13), one O(16), one O(24), one O(3), and one O(6) atom. In the seventh K site, K(7) is bonded in a 6-coordinate geometry to one O(13), one O(16), one O(19), one O(2), one O(21), and one O(4) atom. In the eighth K site, K(8) is bonded in a 5-coordinate geometry to one O(1), one O(12), one O(14), one O(15), and one O(20) atom. Mg(1) is bonded to one O(1), one O(18), one O(22), and one O(3) atom to form MgO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  an edgeedge with one Si(6)O4 tetrahedra. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(13), one O(5), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(7)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(10), one O(14), one O(2), and one O(6) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(11), one O(15), one O(3), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(7)O4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(12), one O(16), one O(4), and one O(8) atom to form corner-sharing SiO4 tetrahedra. In the fifth Si site, Si(5) is bonded to one O(11), one O(17), one O(21), and one O(5) atom to form corner-sharing SiO4 tetrahedra. In the sixth Si site, Si(6) is bonded to one O(12), one O(18), one O(22), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. In the seventh Si site, Si(7) is bonded to one O(19), one O(23), one O(7), and one O(9) atom to form corner-sharing SiO4 tetrahedra. In the eighth Si site, Si(8) is bonded to one O(10), one O(20), one O(24), and one O(8) atom to form corner-sharing SiO4 tetrahedra. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(8), one Mg(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(5), one K(7), and one Si(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one K(6), one Mg(1), and one Si(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one K(5), one K(7), and one Si(4) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one K(2), one Si(1), and one Si(5) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one K(1), one K(6), one Si(2), and one Si(6) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one K(4), one Si(3), and one Si(7) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one K(3), one Si(4), and one Si(8) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one K(1), one Si(1), and one Si(7) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to one K(2), one Si(2), and one Si(8) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one K(3), one Si(3), and one Si(5) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one K(8), one Si(4), and one Si(6) atom. In the thirteenth O site, O(13) is bonded in a distorted single-bond geometry to one K(2), one K(6), one K(7), and one Si(1) atom. In the fourteenth O site, O(14) is bonded in a distorted single-bond geometry to one K(1), one K(5), one K(8), and one Si(2) atom. In the fifteenth O site, O(15) is bonded in a distorted single-bond geometry to one K(3), one K(5), one K(8), and one Si(3) atom. In the sixteenth O site, O(16) is bonded in a distorted single-bond geometry to one K(4), one K(6), one K(7), and one Si(4) atom. In the seventeenth O site, O(17) is bonded in a distorted single-bond geometry to one K(1), one K(3), one K(5), and one Si(5) atom. In the eighteenth O site, O(18) is bonded in a 3-coordinate geometry to one K(2), one Mg(1), and one Si(6) atom. In the nineteenth O site, O(19) is bonded in a distorted single-bond geometry to one K(1), one K(3), one K(7), and one Si(7) atom. In the twentieth O site, O(20) is bonded in a 3-coordinate geometry to one K(4), one K(8), and one Si(8) atom. In the twenty-first O site, O(21) is bonded in a distorted single-bond geometry to one K(2), one K(4), one K(7), and one Si(5) atom. In the twenty-second O site, O(22) is bonded in a 3-coordinate geometry to one K(3), one Mg(1), and one Si(6) atom. In the twenty-third O site, O(23) is bonded in a distorted single-bond geometry to one K(2), one K(4), one K(5), and one Si(7) atom. In the twenty-fourth O site, O(24) is bonded in a 3-coordinate geometry to one K(1), one K(6), and one Si(8) atom. is represented by the CIF file [CIF]
data_K8Mg(SiO3)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.279
_cell_length_b   8.265
_cell_length_c   10.276
_cell_angle_alpha   88.787
_cell_angle_beta   88.930
_cell_angle_gamma   96.332
_symmetry_Int_Tables_number   1
_cell_volume   698.585
_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
  K  K0  1  0.992  0.022  0.735  1.0
  K  K1  1  0.492  0.537  0.740  1.0
  K  K2  1  0.968  0.010  0.262  1.0
  K  K3  1  0.479  0.505  0.263  1.0
  K  K4  1  0.677  0.195  0.516  1.0
  K  K5  1  0.172  0.778  0.984  1.0
  K  K6  1  0.305  0.822  0.484  1.0
  K  K7  1  0.727  0.324  0.016  1.0
  Mg  Mg8  1  0.108  0.394  0.001  1.0
  Si  Si9  1  0.026  0.516  0.708  1.0
  Si  Si10  1  0.513  0.007  0.807  1.0
  Si  Si11  1  0.986  0.473  0.292  1.0
  Si  Si12  1  0.494  0.985  0.193  1.0
  Si  Si13  1  0.820  0.681  0.500  1.0
  Si  Si14  1  0.312  0.188  0.997  1.0
  Si  Si15  1  0.192  0.308  0.501  1.0
  Si  Si16  1  0.689  0.810  0.002  1.0
  O  O17  1  0.977  0.448  0.855  1.0
  O  O18  1  0.486  0.963  0.657  1.0
  O  O19  1  0.052  0.525  0.146  1.0
  O  O20  1  0.524  0.025  0.344  1.0
  O  O21  1  0.866  0.573  0.630  1.0
  O  O22  1  0.346  0.065  0.875  1.0
  O  O23  1  0.145  0.416  0.373  1.0
  O  O24  1  0.664  0.941  0.120  1.0
  O  O25  1  0.079  0.358  0.625  1.0
  O  O26  1  0.549  0.842  0.893  1.0
  O  O27  1  0.933  0.633  0.374  1.0
  O  O28  1  0.442  0.146  0.111  1.0
  O  O29  1  0.171  0.663  0.714  1.0
  O  O30  1  0.666  0.146  0.793  1.0
  O  O31  1  0.838  0.329  0.286  1.0
  O  O32  1  0.353  0.832  0.207  1.0
  O  O33  1  0.850  0.877  0.517  1.0
  O  O34  1  0.345  0.381  0.959  1.0
  O  O35  1  0.159  0.112  0.483  1.0
  O  O36  1  0.662  0.621  0.047  1.0
  O  O37  1  0.625  0.648  0.479  1.0
  O  O38  1  0.122  0.155  0.041  1.0
  O  O39  1  0.386  0.342  0.523  1.0
  O  O40  1  0.874  0.839  0.949  1.0
[/CIF]
.