The structure described by K2ZrSi2O7 crystallizes in the monoclinic C2/m space group. There are six inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(12), one O(14), one O(15), one O(17), one O(18), one O(3), one O(4), and one O(8) atom. In the second K site, K(2) is bonded in a 9-coordinate geometry to one O(1), one O(11), one O(13), one O(16), one O(17), one O(2), one O(3), one O(7), and one O(9) atom. In the third K site, K(3) is bonded in a 10-coordinate geometry to one O(7), one O(8), two equivalent O(10), two equivalent O(14), and four equivalent O(4) atoms. In the fourth K site, K(4) is bonded in a 10-coordinate geometry to one O(1), one O(18), two equivalent O(13), two equivalent O(9), and four equivalent O(2) atoms. In the fifth K site, K(5) is bonded in a 11-coordinate geometry to one O(16), two equivalent O(11), two equivalent O(12), two equivalent O(3), two equivalent O(6), and two equivalent O(9) atoms. In the sixth K site, K(6) is bonded in a 11-coordinate geometry to one O(15), two equivalent O(10), two equivalent O(11), two equivalent O(12), two equivalent O(17), and two equivalent O(5) atoms. There are three inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to one O(1), one O(18), two equivalent O(17), and two equivalent O(2) atoms to form ZrO6 octahedra that share  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Zr site, Zr(2) is bonded to one O(7), one O(8), two equivalent O(3), and two equivalent O(4) atoms to form ZrO6 octahedra that share  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the third Zr site, Zr(3) is bonded to one O(10), one O(11), one O(12), one O(13), one O(14), and one O(9) atom to form ZrO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(10), one O(17), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Zr(1)O6 octahedra,  a cornercorner with one Zr(2)O6 octahedra,  a cornercorner with one Zr(3)O6 octahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 1-36°. In the second Si site, Si(2) is bonded to one O(2), one O(3), one O(6), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Zr(1)O6 octahedra,  a cornercorner with one Zr(2)O6 octahedra,  a cornercorner with one Zr(3)O6 octahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 3-36°. In the third Si site, Si(3) is bonded to one O(15), one O(18), and two equivalent O(14) atoms to form SiO4 tetrahedra that share  a cornercorner with one Zr(1)O6 octahedra, corners with two equivalent Zr(3)O6 octahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 1-29°. In the fourth Si site, Si(4) is bonded to one O(16), one O(7), and two equivalent O(13) atoms to form SiO4 tetrahedra that share  a cornercorner with one Zr(2)O6 octahedra, corners with two equivalent Zr(3)O6 octahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 1-29°. In the fifth Si site, Si(5) is bonded to one O(15), one O(8), and two equivalent O(12) atoms to form SiO4 tetrahedra that share  a cornercorner with one Zr(2)O6 octahedra, corners with two equivalent Zr(3)O6 octahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-41°. In the sixth Si site, Si(6) is bonded to one O(1), one O(16), and two equivalent O(11) atoms to form SiO4 tetrahedra that share  a cornercorner with one Zr(1)O6 octahedra, corners with two equivalent Zr(3)O6 octahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 11-42°. There are eighteen inequivalent O sites. In the first O site, O(16) is bonded in a distorted bent 150 degrees geometry to one K(5), two equivalent K(2), one Si(4), and one Si(6) atom. In the second O site, O(17) is bonded in a distorted linear geometry to one K(1), one K(2), one K(6), one Zr(1), and one Si(1) atom. In the third O site, O(18) is bonded in a distorted linear geometry to one K(4), two equivalent K(1), one Zr(1), and one Si(3) atom. In the fourth O site, O(1) is bonded in a 5-coordinate geometry to one K(4), two equivalent K(2), one Zr(1), and one Si(6) atom. In the fifth O site, O(2) is bonded in a 2-coordinate geometry to one K(2), two equivalent K(4), one Zr(1), and one Si(2) atom. In the sixth O site, O(3) is bonded in a distorted linear geometry to one K(1), one K(2), one K(5), one Zr(2), and one Si(2) atom. In the seventh O site, O(4) is bonded in a 5-coordinate geometry to one K(1), two equivalent K(3), one Zr(2), and one Si(1) atom. In the eighth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent K(6) and two equivalent Si(1) atoms. In the ninth O site, O(6) is bonded in a 2-coordinate geometry to two equivalent K(5) and two equivalent Si(2) atoms. In the tenth O site, O(7) is bonded in a distorted linear geometry to one K(3), two equivalent K(2), one Zr(2), and one Si(4) atom. In the eleventh O site, O(8) is bonded in a 5-coordinate geometry to one K(3), two equivalent K(1), one Zr(2), and one Si(5) atom. In the twelfth O site, O(9) is bonded in a 2-coordinate geometry to one K(2), one K(4), one K(5), one Zr(3), and one Si(2) atom. In the thirteenth O site, O(10) is bonded in a 2-coordinate geometry to one K(3), one K(6), one Zr(3), and one Si(1) atom. In the fourteenth O site, O(11) is bonded in a 2-coordinate geometry to one K(2), one K(5), one K(6), one Zr(3), and one Si(6) atom. In the fifteenth O site, O(12) is bonded in a 2-coordinate geometry to one K(1), one K(5), one K(6), one Zr(3), and one Si(5) atom. In the sixteenth O site, O(13) is bonded in a distorted bent 150 degrees geometry to one K(2), one K(4), one Zr(3), and one Si(4) atom. In the seventeenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(3), one Zr(3), and one Si(3) atom. In the eighteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one K(6), two equivalent K(1), one Si(3), and one Si(5) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2ZrSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.112
_cell_length_b   9.112
_cell_length_c   9.174
_cell_angle_alpha   76.143
_cell_angle_beta   76.143
_cell_angle_gamma   76.301
_symmetry_Int_Tables_number   1
_cell_volume   704.882
_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  0.969  0.476  0.727  1.0
  K  K1  1  0.476  0.969  0.727  1.0
  K  K2  1  0.031  0.524  0.273  1.0
  K  K3  1  0.524  0.031  0.273  1.0
  K  K4  1  0.967  0.967  0.221  1.0
  K  K5  1  0.033  0.033  0.779  1.0
  K  K6  1  0.512  0.512  0.761  1.0
  K  K7  1  0.488  0.488  0.239  1.0
  O  O8  1  0.759  0.759  0.265  1.0
  O  O9  1  0.241  0.241  0.735  1.0
  O  O10  1  0.014  0.742  0.003  1.0
  O  O11  1  0.742  0.014  0.003  1.0
  O  O12  1  0.986  0.258  0.997  1.0
  O  O13  1  0.258  0.986  0.997  1.0
  O  O14  1  0.472  0.201  0.941  1.0
  O  O15  1  0.201  0.472  0.941  1.0
  O  O16  1  0.528  0.799  0.059  1.0
  O  O17  1  0.799  0.528  0.059  1.0
  O  O18  1  0.681  0.319  1.000  1.0
  O  O19  1  0.319  0.681  1.000  1.0
  O  O20  1  0.195  0.195  0.212  1.0
  O  O21  1  0.805  0.805  0.788  1.0
  O  O22  1  0.225  0.739  0.738  1.0
  O  O23  1  0.739  0.225  0.738  1.0
  O  O24  1  0.775  0.261  0.262  1.0
  O  O25  1  0.261  0.775  0.262  1.0
  O  O26  1  0.487  0.727  0.457  1.0
  O  O27  1  0.727  0.487  0.457  1.0
  O  O28  1  0.513  0.273  0.543  1.0
  O  O29  1  0.273  0.513  0.543  1.0
  O  O30  1  0.231  0.992  0.476  1.0
  O  O31  1  0.992  0.231  0.476  1.0
  O  O32  1  0.769  0.008  0.524  1.0
  O  O33  1  0.008  0.769  0.524  1.0
  O  O34  1  0.721  0.721  0.576  1.0
  O  O35  1  0.279  0.279  0.424  1.0
  Si  Si36  1  0.818  0.341  0.082  1.0
  Si  Si37  1  0.341  0.818  0.082  1.0
  Si  Si38  1  0.182  0.659  0.918  1.0
  Si  Si39  1  0.659  0.182  0.918  1.0
  Si  Si40  1  0.832  0.832  0.602  1.0
  Si  Si41  1  0.168  0.168  0.398  1.0
  Si  Si42  1  0.326  0.326  0.569  1.0
  Si  Si43  1  0.674  0.674  0.431  1.0
  Zr  Zr44  1  0.769  0.769  0.024  1.0
  Zr  Zr45  1  0.231  0.231  0.976  1.0
  Zr  Zr46  1  0.247  0.753  0.500  1.0
  Zr  Zr47  1  0.753  0.247  0.500  1.0
[/CIF]
.
The structure described by K2ZrSi2O7 crystallizes in the monoclinic C2/m space group. There are six inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(12), one O(14), one O(15), one O(17), one O(18), one O(3), one O(4), and one O(8) atom. In the second K site, K(2) is bonded in a 9-coordinate geometry to one O(1), one O(11), one O(13), one O(16), one O(17), one O(2), one O(3), one O(7), and one O(9) atom. In the third K site, K(3) is bonded in a 10-coordinate geometry to one O(7), one O(8), two equivalent O(10), two equivalent O(14), and four equivalent O(4) atoms. In the fourth K site, K(4) is bonded in a 10-coordinate geometry to one O(1), one O(18), two equivalent O(13), two equivalent O(9), and four equivalent O(2) atoms. In the fifth K site, K(5) is bonded in a 11-coordinate geometry to one O(16), two equivalent O(11), two equivalent O(12), two equivalent O(3), two equivalent O(6), and two equivalent O(9) atoms. In the sixth K site, K(6) is bonded in a 11-coordinate geometry to one O(15), two equivalent O(10), two equivalent O(11), two equivalent O(12), two equivalent O(17), and two equivalent O(5) atoms. There are three inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to one O(1), one O(18), two equivalent O(17), and two equivalent O(2) atoms to form ZrO6 octahedra that share  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Zr site, Zr(2) is bonded to one O(7), one O(8), two equivalent O(3), and two equivalent O(4) atoms to form ZrO6 octahedra that share  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the third Zr site, Zr(3) is bonded to one O(10), one O(11), one O(12), one O(13), one O(14), and one O(9) atom to form ZrO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(10), one O(17), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Zr(1)O6 octahedra,  a cornercorner with one Zr(2)O6 octahedra,  a cornercorner with one Zr(3)O6 octahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 1-36°. In the second Si site, Si(2) is bonded to one O(2), one O(3), one O(6), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Zr(1)O6 octahedra,  a cornercorner with one Zr(2)O6 octahedra,  a cornercorner with one Zr(3)O6 octahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 3-36°. In the third Si site, Si(3) is bonded to one O(15), one O(18), and two equivalent O(14) atoms to form SiO4 tetrahedra that share  a cornercorner with one Zr(1)O6 octahedra, corners with two equivalent Zr(3)O6 octahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 1-29°. In the fourth Si site, Si(4) is bonded to one O(16), one O(7), and two equivalent O(13) atoms to form SiO4 tetrahedra that share  a cornercorner with one Zr(2)O6 octahedra, corners with two equivalent Zr(3)O6 octahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 1-29°. In the fifth Si site, Si(5) is bonded to one O(15), one O(8), and two equivalent O(12) atoms to form SiO4 tetrahedra that share  a cornercorner with one Zr(2)O6 octahedra, corners with two equivalent Zr(3)O6 octahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-41°. In the sixth Si site, Si(6) is bonded to one O(1), one O(16), and two equivalent O(11) atoms to form SiO4 tetrahedra that share  a cornercorner with one Zr(1)O6 octahedra, corners with two equivalent Zr(3)O6 octahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 11-42°. There are eighteen inequivalent O sites. In the first O site, O(16) is bonded in a distorted bent 150 degrees geometry to one K(5), two equivalent K(2), one Si(4), and one Si(6) atom. In the second O site, O(17) is bonded in a distorted linear geometry to one K(1), one K(2), one K(6), one Zr(1), and one Si(1) atom. In the third O site, O(18) is bonded in a distorted linear geometry to one K(4), two equivalent K(1), one Zr(1), and one Si(3) atom. In the fourth O site, O(1) is bonded in a 5-coordinate geometry to one K(4), two equivalent K(2), one Zr(1), and one Si(6) atom. In the fifth O site, O(2) is bonded in a 2-coordinate geometry to one K(2), two equivalent K(4), one Zr(1), and one Si(2) atom. In the sixth O site, O(3) is bonded in a distorted linear geometry to one K(1), one K(2), one K(5), one Zr(2), and one Si(2) atom. In the seventh O site, O(4) is bonded in a 5-coordinate geometry to one K(1), two equivalent K(3), one Zr(2), and one Si(1) atom. In the eighth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent K(6) and two equivalent Si(1) atoms. In the ninth O site, O(6) is bonded in a 2-coordinate geometry to two equivalent K(5) and two equivalent Si(2) atoms. In the tenth O site, O(7) is bonded in a distorted linear geometry to one K(3), two equivalent K(2), one Zr(2), and one Si(4) atom. In the eleventh O site, O(8) is bonded in a 5-coordinate geometry to one K(3), two equivalent K(1), one Zr(2), and one Si(5) atom. In the twelfth O site, O(9) is bonded in a 2-coordinate geometry to one K(2), one K(4), one K(5), one Zr(3), and one Si(2) atom. In the thirteenth O site, O(10) is bonded in a 2-coordinate geometry to one K(3), one K(6), one Zr(3), and one Si(1) atom. In the fourteenth O site, O(11) is bonded in a 2-coordinate geometry to one K(2), one K(5), one K(6), one Zr(3), and one Si(6) atom. In the fifteenth O site, O(12) is bonded in a 2-coordinate geometry to one K(1), one K(5), one K(6), one Zr(3), and one Si(5) atom. In the sixteenth O site, O(13) is bonded in a distorted bent 150 degrees geometry to one K(2), one K(4), one Zr(3), and one Si(4) atom. In the seventeenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(3), one Zr(3), and one Si(3) atom. In the eighteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one K(6), two equivalent K(1), one Si(3), and one Si(5) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2ZrSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.112
_cell_length_b   9.112
_cell_length_c   9.174
_cell_angle_alpha   76.143
_cell_angle_beta   76.143
_cell_angle_gamma   76.301
_symmetry_Int_Tables_number   1
_cell_volume   704.882
_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  0.969  0.476  0.727  1.0
  K  K1  1  0.476  0.969  0.727  1.0
  K  K2  1  0.031  0.524  0.273  1.0
  K  K3  1  0.524  0.031  0.273  1.0
  K  K4  1  0.967  0.967  0.221  1.0
  K  K5  1  0.033  0.033  0.779  1.0
  K  K6  1  0.512  0.512  0.761  1.0
  K  K7  1  0.488  0.488  0.239  1.0
  O  O8  1  0.759  0.759  0.265  1.0
  O  O9  1  0.241  0.241  0.735  1.0
  O  O10  1  0.014  0.742  0.003  1.0
  O  O11  1  0.742  0.014  0.003  1.0
  O  O12  1  0.986  0.258  0.997  1.0
  O  O13  1  0.258  0.986  0.997  1.0
  O  O14  1  0.472  0.201  0.941  1.0
  O  O15  1  0.201  0.472  0.941  1.0
  O  O16  1  0.528  0.799  0.059  1.0
  O  O17  1  0.799  0.528  0.059  1.0
  O  O18  1  0.681  0.319  1.000  1.0
  O  O19  1  0.319  0.681  1.000  1.0
  O  O20  1  0.195  0.195  0.212  1.0
  O  O21  1  0.805  0.805  0.788  1.0
  O  O22  1  0.225  0.739  0.738  1.0
  O  O23  1  0.739  0.225  0.738  1.0
  O  O24  1  0.775  0.261  0.262  1.0
  O  O25  1  0.261  0.775  0.262  1.0
  O  O26  1  0.487  0.727  0.457  1.0
  O  O27  1  0.727  0.487  0.457  1.0
  O  O28  1  0.513  0.273  0.543  1.0
  O  O29  1  0.273  0.513  0.543  1.0
  O  O30  1  0.231  0.992  0.476  1.0
  O  O31  1  0.992  0.231  0.476  1.0
  O  O32  1  0.769  0.008  0.524  1.0
  O  O33  1  0.008  0.769  0.524  1.0
  O  O34  1  0.721  0.721  0.576  1.0
  O  O35  1  0.279  0.279  0.424  1.0
  Si  Si36  1  0.818  0.341  0.082  1.0
  Si  Si37  1  0.341  0.818  0.082  1.0
  Si  Si38  1  0.182  0.659  0.918  1.0
  Si  Si39  1  0.659  0.182  0.918  1.0
  Si  Si40  1  0.832  0.832  0.602  1.0
  Si  Si41  1  0.168  0.168  0.398  1.0
  Si  Si42  1  0.326  0.326  0.569  1.0
  Si  Si43  1  0.674  0.674  0.431  1.0
  Zr  Zr44  1  0.769  0.769  0.024  1.0
  Zr  Zr45  1  0.231  0.231  0.976  1.0
  Zr  Zr46  1  0.247  0.753  0.500  1.0
  Zr  Zr47  1  0.753  0.247  0.500  1.0
[/CIF]
.