Na3La(AsO4)2 crystallizes in the trigonal P-3m1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a single-bond geometry to one O(1) atom. In the second Na site, Na(2) is bonded in a distorted hexagonal planar geometry to six equivalent O(2) atoms. La(1) is bonded to six equivalent O(2) atoms to form LaO6 octahedra that share corners with six equivalent As(1)O4 tetrahedra. As(1) is bonded to one O(1) and three equivalent O(2) atoms to form AsO4 tetrahedra that share corners with three equivalent La(1)O6 octahedra. The corner-sharing octahedral tilt angles are 15°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Na(1) and one As(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Na(2), one La(1), and one As(1) atom.
Na3La(AsO4)2 crystallizes in the trigonal P-3m1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a single-bond geometry to one O(1) atom. The Na(1)-O(1) bond length is 2.15 Å. In the second Na site, Na(2) is bonded in a distorted hexagonal planar geometry to six equivalent O(2) atoms. All Na(2)-O(2) bond lengths are 2.94 Å. La(1) is bonded to six equivalent O(2) atoms to form LaO6 octahedra that share corners with six equivalent As(1)O4 tetrahedra. All La(1)-O(2) bond lengths are 2.36 Å. As(1) is bonded to one O(1) and three equivalent O(2) atoms to form AsO4 tetrahedra that share corners with three equivalent La(1)O6 octahedra. The corner-sharing octahedral tilt angles are 15°. The As(1)-O(1) bond length is 1.67 Å. All As(1)-O(2) bond lengths are 1.74 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Na(1) and one As(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Na(2), one La(1), and one As(1) atom.