La2(SiO3)3 crystallizes in the hexagonal P6_3/m space group. La(1) is bonded to six equivalent O(2) atoms to form distorted LaO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with three equivalent La(1)O6 octahedra. Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with four equivalent La(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-61°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent La(1) and one Si(1) atom.
La2(SiO3)3 crystallizes in the hexagonal P6_3/m space group. La(1) is bonded to six equivalent O(2) atoms to form distorted LaO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with three equivalent La(1)O6 octahedra. There are three shorter (2.39 Å) and three longer (2.53 Å) La(1)-O(2) bond lengths. Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with four equivalent La(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-61°. There is one shorter (1.65 Å) and one longer (1.66 Å) Si(1)-O(1) bond length. Both Si(1)-O(2) bond lengths are 1.63 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent La(1) and one Si(1) atom.