KTaSi2O7 crystallizes in the tetragonal P4/mbm space group. K(1) is bonded in a 12-coordinate geometry to two equivalent O(3), two equivalent O(4), and eight equivalent O(1) atoms. Ta(1) is bonded to one O(3), one O(5), and four equivalent O(1) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra and corners with four equivalent Si(1)O4 tetrahedra. The corner-sharing octahedra are not tilted. Si(1) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with two equivalent Ta(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 23°. There are five inequivalent O sites. In the first O site, O(2) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(3) is bonded in a linear geometry to four equivalent K(1) and two equivalent Ta(1) atoms. In the third O site, O(4) is bonded in a 2-coordinate geometry to two equivalent K(1) and two equivalent Si(1) atoms. In the fourth O site, O(5) is bonded in a linear geometry to two equivalent Ta(1) atoms. In the fifth O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Ta(1), and one Si(1) atom.
KTaSi2O7 crystallizes in the tetragonal P4/mbm space group. K(1) is bonded in a 12-coordinate geometry to two equivalent O(3), two equivalent O(4), and eight equivalent O(1) atoms. Both K(1)-O(3) bond lengths are 3.27 Å. Both K(1)-O(4) bond lengths are 2.88 Å. There are four shorter (2.89 Å) and four longer (3.09 Å) K(1)-O(1) bond lengths. Ta(1) is bonded to one O(3), one O(5), and four equivalent O(1) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra and corners with four equivalent Si(1)O4 tetrahedra. The corner-sharing octahedra are not tilted. The Ta(1)-O(3) bond length is 1.99 Å. The Ta(1)-O(5) bond length is 2.01 Å. All Ta(1)-O(1) bond lengths are 2.00 Å. Si(1) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with two equivalent Ta(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 23°. The Si(1)-O(2) bond length is 1.60 Å. The Si(1)-O(4) bond length is 1.66 Å. Both Si(1)-O(1) bond lengths are 1.62 Å. There are five inequivalent O sites. In the first O site, O(2) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(3) is bonded in a linear geometry to four equivalent K(1) and two equivalent Ta(1) atoms. In the third O site, O(4) is bonded in a 2-coordinate geometry to two equivalent K(1) and two equivalent Si(1) atoms. In the fourth O site, O(5) is bonded in a linear geometry to two equivalent Ta(1) atoms. In the fifth O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Ta(1), and one Si(1) atom.