Na4BaTi2Si10(BO15)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(7), one O(8), and one O(9) atom. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(10), one O(14), one O(15), one O(4), one O(6), and one O(7) atom. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(11), two equivalent O(12), two equivalent O(13), two equivalent O(2), and two equivalent O(8) atoms. Ti(1) is bonded to one O(11), one O(12), one O(13), one O(14), one O(15), and one O(4) atom to form distorted TiO6 octahedra that share  an edgeedge with one Si(3)O4 tetrahedra,  an edgeedge with one Si(4)O4 tetrahedra, and  an edgeedge with one Si(5)O4 tetrahedra. B(1) is bonded to one O(1), one O(7), one O(8), and one O(9) atom to form BO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and  an edgeedge with one Si(2)O5 trigonal bipyramid. There are five inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(6), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and corners with two equivalent B(1)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(5), one O(7), one O(8), and two equivalent O(3) atoms to form distorted SiO5 trigonal bipyramids that share  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(5)O4 tetrahedra,  an edgeedge with one B(1)O4 tetrahedra, and  an edgeedge with one Si(2)O5 trigonal bipyramid. In the third Si site, Si(3) is bonded to one O(12), one O(2), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  an edgeedge with one Ti(1)O6 octahedra. In the fourth Si site, Si(4) is bonded to one O(11), one O(15), one O(2), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(2)O5 trigonal bipyramid, and  an edgeedge with one Ti(1)O6 octahedra. In the fifth Si site, Si(5) is bonded to one O(10), one O(13), one O(14), and one O(3) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Si(2)O5 trigonal bipyramids, and  an edgeedge with one Ti(1)O6 octahedra. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one B(1) and one Si(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Si(3), and one Si(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Si(5) and two equivalent Si(2) atoms. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Na(2), one Ti(1), and one Si(3) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Na(2), one Si(1), and one Si(3) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), one B(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a distorted L-shaped geometry to one Na(1), one Ba(1), one B(1), and one Si(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Na(1), one B(1), and one Si(1) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to one Na(1), one Na(2), one Si(1), and one Si(5) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Na(1), one Ba(1), one Ti(1), and one Si(4) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Na(1), one Ba(1), one Ti(1), and one Si(3) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to one Na(1), one Ba(1), one Ti(1), and one Si(5) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Na(2), one Ti(1), and one Si(5) atom. In the fifteenth O site, O(15) is bonded in a 3-coordinate geometry to one Na(2), one Ti(1), and one Si(4) atom.
Na4BaTi2Si10(BO15)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(7), one O(8), and one O(9) atom. The Na(1)-O(10) bond length is 2.77 Å. The Na(1)-O(11) bond length is 2.42 Å. The Na(1)-O(12) bond length is 2.29 Å. The Na(1)-O(13) bond length is 2.68 Å. The Na(1)-O(7) bond length is 2.87 Å. The Na(1)-O(8) bond length is 2.93 Å. The Na(1)-O(9) bond length is 2.38 Å. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(10), one O(14), one O(15), one O(4), one O(6), and one O(7) atom. The Na(2)-O(10) bond length is 2.88 Å. The Na(2)-O(14) bond length is 2.48 Å. The Na(2)-O(15) bond length is 2.47 Å. The Na(2)-O(4) bond length is 2.30 Å. The Na(2)-O(6) bond length is 2.82 Å. The Na(2)-O(7) bond length is 2.29 Å. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(11), two equivalent O(12), two equivalent O(13), two equivalent O(2), and two equivalent O(8) atoms. Both Ba(1)-O(11) bond lengths are 3.02 Å. Both Ba(1)-O(12) bond lengths are 2.74 Å. Both Ba(1)-O(13) bond lengths are 2.88 Å. Both Ba(1)-O(2) bond lengths are 2.78 Å. Both Ba(1)-O(8) bond lengths are 2.79 Å. Ti(1) is bonded to one O(11), one O(12), one O(13), one O(14), one O(15), and one O(4) atom to form distorted TiO6 octahedra that share  an edgeedge with one Si(3)O4 tetrahedra,  an edgeedge with one Si(4)O4 tetrahedra, and  an edgeedge with one Si(5)O4 tetrahedra. The Ti(1)-O(11) bond length is 2.02 Å. The Ti(1)-O(12) bond length is 1.99 Å. The Ti(1)-O(13) bond length is 1.98 Å. The Ti(1)-O(14) bond length is 2.00 Å. The Ti(1)-O(15) bond length is 2.01 Å. The Ti(1)-O(4) bond length is 2.02 Å. B(1) is bonded to one O(1), one O(7), one O(8), and one O(9) atom to form BO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and  an edgeedge with one Si(2)O5 trigonal bipyramid. The B(1)-O(1) bond length is 1.44 Å. The B(1)-O(7) bond length is 1.56 Å. The B(1)-O(8) bond length is 1.50 Å. The B(1)-O(9) bond length is 1.49 Å. There are five inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(6), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and corners with two equivalent B(1)O4 tetrahedra. The Si(1)-O(1) bond length is 1.60 Å. The Si(1)-O(10) bond length is 1.67 Å. The Si(1)-O(6) bond length is 1.66 Å. The Si(1)-O(9) bond length is 1.65 Å. In the second Si site, Si(2) is bonded to one O(5), one O(7), one O(8), and two equivalent O(3) atoms to form distorted SiO5 trigonal bipyramids that share  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(5)O4 tetrahedra,  an edgeedge with one B(1)O4 tetrahedra, and  an edgeedge with one Si(2)O5 trigonal bipyramid. The Si(2)-O(5) bond length is 1.63 Å. The Si(2)-O(7) bond length is 1.68 Å. The Si(2)-O(8) bond length is 1.74 Å. There is one shorter (1.74 Å) and one longer (2.01 Å) Si(2)-O(3) bond length. In the third Si site, Si(3) is bonded to one O(12), one O(2), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  an edgeedge with one Ti(1)O6 octahedra. The Si(3)-O(12) bond length is 1.66 Å. The Si(3)-O(2) bond length is 1.67 Å. The Si(3)-O(4) bond length is 1.61 Å. The Si(3)-O(6) bond length is 1.64 Å. In the fourth Si site, Si(4) is bonded to one O(11), one O(15), one O(2), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(2)O5 trigonal bipyramid, and  an edgeedge with one Ti(1)O6 octahedra. The Si(4)-O(11) bond length is 1.66 Å. The Si(4)-O(15) bond length is 1.62 Å. The Si(4)-O(2) bond length is 1.67 Å. The Si(4)-O(5) bond length is 1.63 Å. In the fifth Si site, Si(5) is bonded to one O(10), one O(13), one O(14), and one O(3) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Si(2)O5 trigonal bipyramids, and  an edgeedge with one Ti(1)O6 octahedra. The Si(5)-O(10) bond length is 1.66 Å. The Si(5)-O(13) bond length is 1.64 Å. The Si(5)-O(14) bond length is 1.63 Å. The Si(5)-O(3) bond length is 1.69 Å. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one B(1) and one Si(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Si(3), and one Si(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Si(5) and two equivalent Si(2) atoms. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Na(2), one Ti(1), and one Si(3) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Na(2), one Si(1), and one Si(3) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), one B(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a distorted L-shaped geometry to one Na(1), one Ba(1), one B(1), and one Si(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Na(1), one B(1), and one Si(1) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to one Na(1), one Na(2), one Si(1), and one Si(5) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Na(1), one Ba(1), one Ti(1), and one Si(4) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Na(1), one Ba(1), one Ti(1), and one Si(3) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to one Na(1), one Ba(1), one Ti(1), and one Si(5) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Na(2), one Ti(1), and one Si(5) atom. In the fifteenth O site, O(15) is bonded in a 3-coordinate geometry to one Na(2), one Ti(1), and one Si(4) atom.