La2SiO5 crystallizes in the monoclinic C2/c space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(2), and two equivalent O(5) atoms. In the second La site, La(2) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to two equivalent La(2) and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent La(1) and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one La(1), two equivalent La(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one La(1), one La(2), and one Si(1) atom. In the fifth O site, O(5) is bonded to two equivalent La(1) and two equivalent La(2) atoms to form edge-sharing OLa4 tetrahedra.
La2SiO5 crystallizes in the monoclinic C2/c space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(2), and two equivalent O(5) atoms. The La(1)-O(3) bond length is 2.45 Å. The La(1)-O(4) bond length is 2.43 Å. There is one shorter (2.46 Å) and one longer (2.48 Å) La(1)-O(2) bond length. There is one shorter (2.37 Å) and one longer (2.41 Å) La(1)-O(5) bond length. In the second La site, La(2) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms. The La(2)-O(4) bond length is 2.48 Å. There is one shorter (2.49 Å) and one longer (2.53 Å) La(2)-O(1) bond length. There is one shorter (2.52 Å) and one longer (2.70 Å) La(2)-O(3) bond length. There is one shorter (2.39 Å) and one longer (2.47 Å) La(2)-O(5) bond length. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Si(1)-O(1) bond length is 1.64 Å. The Si(1)-O(2) bond length is 1.64 Å. The Si(1)-O(3) bond length is 1.64 Å. The Si(1)-O(4) bond length is 1.62 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to two equivalent La(2) and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent La(1) and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one La(1), two equivalent La(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one La(1), one La(2), and one Si(1) atom. In the fifth O site, O(5) is bonded to two equivalent La(1) and two equivalent La(2) atoms to form edge-sharing OLa4 tetrahedra.