NaBeSi3O8 crystallizes in the monoclinic C2/c space group. Na(1) is bonded in a 3-coordinate geometry to one O(2), one O(6), and one O(9) atom. Be(1) is bonded to one O(1), one O(2), one O(4), and one O(9) atom to form BeO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Be(1)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(2), one O(5), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Be(1)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(4), one O(6), one O(7), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Be(1)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. There are nine inequivalent O sites. In the first O site, O(8) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the second O site, O(9) is bonded in a 3-coordinate geometry to one Na(1), one Be(1), and one Si(2) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Be(1) and one Si(1) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Be(1), and one Si(2) atom. In the fifth O site, O(3) is bonded in a linear geometry to two equivalent Si(1) atoms. In the sixth O site, O(4) is bonded in a bent 150 degrees geometry to one Be(1) and one Si(3) atom. In the seventh O site, O(5) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the eighth O site, O(6) is bonded in a distorted trigonal planar geometry to one Na(1), one Si(1), and one Si(3) atom. In the ninth O site, O(7) is bonded in a linear geometry to two equivalent Si(3) atoms.
NaBeSi3O8 crystallizes in the monoclinic C2/c space group. Na(1) is bonded in a 3-coordinate geometry to one O(2), one O(6), and one O(9) atom. The Na(1)-O(2) bond length is 2.29 Å. The Na(1)-O(6) bond length is 2.54 Å. The Na(1)-O(9) bond length is 2.24 Å. Be(1) is bonded to one O(1), one O(2), one O(4), and one O(9) atom to form BeO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The Be(1)-O(1) bond length is 1.63 Å. The Be(1)-O(2) bond length is 1.68 Å. The Be(1)-O(4) bond length is 1.58 Å. The Be(1)-O(9) bond length is 1.69 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Be(1)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The Si(1)-O(1) bond length is 1.61 Å. The Si(1)-O(3) bond length is 1.62 Å. The Si(1)-O(5) bond length is 1.65 Å. The Si(1)-O(6) bond length is 1.66 Å. In the second Si site, Si(2) is bonded to one O(2), one O(5), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Be(1)O4 tetrahedra. The Si(2)-O(2) bond length is 1.64 Å. The Si(2)-O(5) bond length is 1.66 Å. The Si(2)-O(8) bond length is 1.64 Å. The Si(2)-O(9) bond length is 1.63 Å. In the third Si site, Si(3) is bonded to one O(4), one O(6), one O(7), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Be(1)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The Si(3)-O(4) bond length is 1.59 Å. The Si(3)-O(6) bond length is 1.67 Å. The Si(3)-O(7) bond length is 1.64 Å. The Si(3)-O(8) bond length is 1.65 Å. There are nine inequivalent O sites. In the first O site, O(8) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the second O site, O(9) is bonded in a 3-coordinate geometry to one Na(1), one Be(1), and one Si(2) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Be(1) and one Si(1) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Be(1), and one Si(2) atom. In the fifth O site, O(3) is bonded in a linear geometry to two equivalent Si(1) atoms. In the sixth O site, O(4) is bonded in a bent 150 degrees geometry to one Be(1) and one Si(3) atom. In the seventh O site, O(5) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the eighth O site, O(6) is bonded in a distorted trigonal planar geometry to one Na(1), one Si(1), and one Si(3) atom. In the ninth O site, O(7) is bonded in a linear geometry to two equivalent Si(3) atoms.