The compound described by K4SiO4 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent K sites. In the first K site, K(1) is bonded to one O(2), one O(4), and two equivalent O(3) atoms to form distorted KO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra and  an edgeedge with one K(1)O4 tetrahedra. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(4), two equivalent O(2), and three equivalent O(1) atoms. In the third K site, K(3) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), and two equivalent O(1) atoms. In the fourth K site, K(4) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(3), and two equivalent O(4) atoms. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent K(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent K(3), three equivalent K(2), and one Si(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one K(1), one K(3), one K(4), two equivalent K(2), and one Si(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one K(3), two equivalent K(1), two equivalent K(4), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one K(1), one K(2), one K(3), two equivalent K(4), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K4SiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.421
_cell_length_b   10.317
_cell_length_c   10.331
_cell_angle_alpha   67.371
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   631.674
_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
  K  K0  1  0.666  0.888  0.633  1.0
  K  K1  1  0.334  0.112  0.367  1.0
  K  K2  1  0.834  0.388  0.633  1.0
  K  K3  1  0.593  0.301  0.063  1.0
  K  K4  1  0.093  0.199  0.937  1.0
  K  K5  1  0.407  0.699  0.937  1.0
  K  K6  1  0.907  0.801  0.063  1.0
  K  K7  1  0.610  0.083  0.840  1.0
  K  K8  1  0.110  0.417  0.160  1.0
  K  K9  1  0.390  0.917  0.160  1.0
  K  K10  1  0.890  0.583  0.840  1.0
  K  K11  1  0.687  0.701  0.429  1.0
  K  K12  1  0.187  0.799  0.571  1.0
  K  K13  1  0.313  0.299  0.571  1.0
  K  K14  1  0.813  0.201  0.429  1.0
  K  K15  1  0.166  0.612  0.367  1.0
  Si  Si16  1  0.368  0.490  0.759  1.0
  Si  Si17  1  0.868  0.010  0.241  1.0
  Si  Si18  1  0.132  0.990  0.759  1.0
  Si  Si19  1  0.632  0.510  0.241  1.0
  O  O20  1  0.235  0.969  0.912  1.0
  O  O21  1  0.999  0.154  0.222  1.0
  O  O22  1  0.499  0.346  0.778  1.0
  O  O23  1  0.001  0.846  0.778  1.0
  O  O24  1  0.735  0.531  0.088  1.0
  O  O25  1  0.765  0.031  0.088  1.0
  O  O26  1  0.265  0.469  0.912  1.0
  O  O27  1  0.323  0.015  0.643  1.0
  O  O28  1  0.823  0.485  0.357  1.0
  O  O29  1  0.677  0.985  0.357  1.0
  O  O30  1  0.177  0.515  0.643  1.0
  O  O31  1  0.023  0.870  0.300  1.0
  O  O32  1  0.523  0.630  0.700  1.0
  O  O33  1  0.977  0.130  0.700  1.0
  O  O34  1  0.477  0.370  0.300  1.0
  O  O35  1  0.501  0.654  0.222  1.0
[/CIF]
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The compound described by K4SiO4 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent K sites. In the first K site, K(1) is bonded to one O(2), one O(4), and two equivalent O(3) atoms to form distorted KO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra and  an edgeedge with one K(1)O4 tetrahedra. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(4), two equivalent O(2), and three equivalent O(1) atoms. In the third K site, K(3) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), and two equivalent O(1) atoms. In the fourth K site, K(4) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(3), and two equivalent O(4) atoms. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent K(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent K(3), three equivalent K(2), and one Si(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one K(1), one K(3), one K(4), two equivalent K(2), and one Si(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one K(3), two equivalent K(1), two equivalent K(4), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one K(1), one K(2), one K(3), two equivalent K(4), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K4SiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.421
_cell_length_b   10.317
_cell_length_c   10.331
_cell_angle_alpha   67.371
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   631.674
_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
  K  K0  1  0.666  0.888  0.633  1.0
  K  K1  1  0.334  0.112  0.367  1.0
  K  K2  1  0.834  0.388  0.633  1.0
  K  K3  1  0.593  0.301  0.063  1.0
  K  K4  1  0.093  0.199  0.937  1.0
  K  K5  1  0.407  0.699  0.937  1.0
  K  K6  1  0.907  0.801  0.063  1.0
  K  K7  1  0.610  0.083  0.840  1.0
  K  K8  1  0.110  0.417  0.160  1.0
  K  K9  1  0.390  0.917  0.160  1.0
  K  K10  1  0.890  0.583  0.840  1.0
  K  K11  1  0.687  0.701  0.429  1.0
  K  K12  1  0.187  0.799  0.571  1.0
  K  K13  1  0.313  0.299  0.571  1.0
  K  K14  1  0.813  0.201  0.429  1.0
  K  K15  1  0.166  0.612  0.367  1.0
  Si  Si16  1  0.368  0.490  0.759  1.0
  Si  Si17  1  0.868  0.010  0.241  1.0
  Si  Si18  1  0.132  0.990  0.759  1.0
  Si  Si19  1  0.632  0.510  0.241  1.0
  O  O20  1  0.235  0.969  0.912  1.0
  O  O21  1  0.999  0.154  0.222  1.0
  O  O22  1  0.499  0.346  0.778  1.0
  O  O23  1  0.001  0.846  0.778  1.0
  O  O24  1  0.735  0.531  0.088  1.0
  O  O25  1  0.765  0.031  0.088  1.0
  O  O26  1  0.265  0.469  0.912  1.0
  O  O27  1  0.323  0.015  0.643  1.0
  O  O28  1  0.823  0.485  0.357  1.0
  O  O29  1  0.677  0.985  0.357  1.0
  O  O30  1  0.177  0.515  0.643  1.0
  O  O31  1  0.023  0.870  0.300  1.0
  O  O32  1  0.523  0.630  0.700  1.0
  O  O33  1  0.977  0.130  0.700  1.0
  O  O34  1  0.477  0.370  0.300  1.0
  O  O35  1  0.501  0.654  0.222  1.0
[/CIF]
.