Sr4Nb3PO14 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(13), one O(6), one O(7), two equivalent O(11), two equivalent O(5), and two equivalent O(8) atoms. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one O(14), one O(5), one O(8), two equivalent O(6), and two equivalent O(7) atoms. In the third Sr site, Sr(3) is bonded to one O(13), one O(2), two equivalent O(1), two equivalent O(10), two equivalent O(11), two equivalent O(3), and two equivalent O(9) atoms to form distorted SrO12 cuboctahedra that share corners with two equivalent Sr(3)O12 cuboctahedra, corners with four equivalent Sr(4)O12 cuboctahedra,  a cornercorner with one P(1)O4 tetrahedra,  an edgeedge with one P(1)O4 tetrahedra, faces with two equivalent Sr(3)O12 cuboctahedra, faces with two equivalent Sr(4)O12 cuboctahedra, faces with two equivalent Nb(2)O6 octahedra, and faces with four equivalent Nb(3)O6 octahedra. In the fourth Sr site, Sr(4) is bonded to one O(1), one O(14), two equivalent O(10), two equivalent O(12), two equivalent O(2), two equivalent O(4), and two equivalent O(9) atoms to form distorted SrO12 cuboctahedra that share corners with two equivalent Sr(4)O12 cuboctahedra, corners with four equivalent Sr(3)O12 cuboctahedra, faces with two equivalent Sr(3)O12 cuboctahedra, faces with two equivalent Sr(4)O12 cuboctahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, and faces with four equivalent Nb(2)O6 octahedra. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(12), one O(4), one O(6), one O(7), and two equivalent O(14) atoms to form distorted NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and faces with two equivalent Sr(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 6-33°. In the second Nb site, Nb(2) is bonded to one O(10), one O(12), one O(4), one O(9), and two equivalent O(2) atoms to form distorted NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, faces with two equivalent Sr(3)O12 cuboctahedra, and faces with four equivalent Sr(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 2-33°. In the third Nb site, Nb(3) is bonded to one O(10), one O(11), one O(3), one O(9), and two equivalent O(1) atoms to form NbO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, faces with two equivalent Sr(4)O12 cuboctahedra, and faces with four equivalent Sr(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 2-16°. P(1) is bonded to one O(13), one O(3), one O(5), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Sr(3)O12 cuboctahedra,  a cornercorner with one Nb(3)O6 octahedra, and  an edgeedge with one Sr(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 51°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Sr(4), two equivalent Sr(3), and two equivalent Nb(3) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Sr(3), two equivalent Sr(4), and two equivalent Nb(2) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(3), one Nb(3), and one P(1) atom. In the fourth O site, O(4) is bonded to two equivalent Sr(4), one Nb(1), and one Nb(2) atom to form distorted OSr2Nb2 tetrahedra that share corners with three equivalent O(10)Sr4Nb2 octahedra,  a cornercorner with one O(7)Sr3Nb tetrahedra, corners with two equivalent O(4)Sr2Nb2 tetrahedra, and  an edgeedge with one O(10)Sr4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 8-18°. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Sr(2), two equivalent Sr(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 1-coordinate geometry to one Sr(1), two equivalent Sr(2), and one Nb(1) atom. In the seventh O site, O(7) is bonded to one Sr(1), two equivalent Sr(2), and one Nb(1) atom to form distorted OSr3Nb tetrahedra that share  a cornercorner with one O(4)Sr2Nb2 tetrahedra and corners with two equivalent O(7)Sr3Nb tetrahedra. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Sr(2), two equivalent Sr(1), and one P(1) atom. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to two equivalent Sr(3), two equivalent Sr(4), one Nb(2), and one Nb(3) atom. In the tenth O site, O(10) is bonded to two equivalent Sr(3), two equivalent Sr(4), one Nb(2), and one Nb(3) atom to form distorted OSr4Nb2 octahedra that share corners with three equivalent O(4)Sr2Nb2 tetrahedra, edges with two equivalent O(10)Sr4Nb2 octahedra, and  an edgeedge with one O(4)Sr2Nb2 tetrahedra. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to two equivalent Sr(1), two equivalent Sr(3), and one Nb(3) atom. In the twelfth O site, O(12) is bonded in a 1-coordinate geometry to two equivalent Sr(4), one Nb(1), and one Nb(2) atom. In the thirteenth O site, O(13) is bonded in a distorted single-bond geometry to one Sr(1), one Sr(3), and one P(1) atom. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Sr(2), one Sr(4), and two equivalent Nb(1) atoms.
Sr4Nb3PO14 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(13), one O(6), one O(7), two equivalent O(11), two equivalent O(5), and two equivalent O(8) atoms. The Sr(1)-O(13) bond length is 2.72 Å. The Sr(1)-O(6) bond length is 3.06 Å. The Sr(1)-O(7) bond length is 2.67 Å. There is one shorter (2.86 Å) and one longer (2.97 Å) Sr(1)-O(11) bond length. There is one shorter (2.60 Å) and one longer (2.67 Å) Sr(1)-O(5) bond length. There is one shorter (2.52 Å) and one longer (2.71 Å) Sr(1)-O(8) bond length. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one O(14), one O(5), one O(8), two equivalent O(6), and two equivalent O(7) atoms. The Sr(2)-O(14) bond length is 3.06 Å. The Sr(2)-O(5) bond length is 2.60 Å. The Sr(2)-O(8) bond length is 2.59 Å. There is one shorter (2.54 Å) and one longer (2.56 Å) Sr(2)-O(6) bond length. There is one shorter (2.49 Å) and one longer (2.55 Å) Sr(2)-O(7) bond length. In the third Sr site, Sr(3) is bonded to one O(13), one O(2), two equivalent O(1), two equivalent O(10), two equivalent O(11), two equivalent O(3), and two equivalent O(9) atoms to form distorted SrO12 cuboctahedra that share corners with two equivalent Sr(3)O12 cuboctahedra, corners with four equivalent Sr(4)O12 cuboctahedra,  a cornercorner with one P(1)O4 tetrahedra,  an edgeedge with one P(1)O4 tetrahedra, faces with two equivalent Sr(3)O12 cuboctahedra, faces with two equivalent Sr(4)O12 cuboctahedra, faces with two equivalent Nb(2)O6 octahedra, and faces with four equivalent Nb(3)O6 octahedra. The Sr(3)-O(13) bond length is 2.59 Å. The Sr(3)-O(2) bond length is 2.81 Å. There is one shorter (2.66 Å) and one longer (3.14 Å) Sr(3)-O(1) bond length. There is one shorter (2.88 Å) and one longer (2.89 Å) Sr(3)-O(10) bond length. Both Sr(3)-O(11) bond lengths are 3.06 Å. There is one shorter (2.57 Å) and one longer (2.66 Å) Sr(3)-O(3) bond length. There is one shorter (2.85 Å) and one longer (2.88 Å) Sr(3)-O(9) bond length. In the fourth Sr site, Sr(4) is bonded to one O(1), one O(14), two equivalent O(10), two equivalent O(12), two equivalent O(2), two equivalent O(4), and two equivalent O(9) atoms to form distorted SrO12 cuboctahedra that share corners with two equivalent Sr(4)O12 cuboctahedra, corners with four equivalent Sr(3)O12 cuboctahedra, faces with two equivalent Sr(3)O12 cuboctahedra, faces with two equivalent Sr(4)O12 cuboctahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, and faces with four equivalent Nb(2)O6 octahedra. The Sr(4)-O(1) bond length is 2.79 Å. The Sr(4)-O(14) bond length is 2.64 Å. There is one shorter (2.90 Å) and one longer (2.92 Å) Sr(4)-O(10) bond length. There is one shorter (2.95 Å) and one longer (2.96 Å) Sr(4)-O(12) bond length. There is one shorter (2.78 Å) and one longer (3.02 Å) Sr(4)-O(2) bond length. Both Sr(4)-O(4) bond lengths are 2.56 Å. There is one shorter (3.00 Å) and one longer (3.01 Å) Sr(4)-O(9) bond length. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(12), one O(4), one O(6), one O(7), and two equivalent O(14) atoms to form distorted NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and faces with two equivalent Sr(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 6-33°. The Nb(1)-O(12) bond length is 2.34 Å. The Nb(1)-O(4) bond length is 2.16 Å. The Nb(1)-O(6) bond length is 1.85 Å. The Nb(1)-O(7) bond length is 1.88 Å. There is one shorter (2.05 Å) and one longer (2.07 Å) Nb(1)-O(14) bond length. In the second Nb site, Nb(2) is bonded to one O(10), one O(12), one O(4), one O(9), and two equivalent O(2) atoms to form distorted NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, faces with two equivalent Sr(3)O12 cuboctahedra, and faces with four equivalent Sr(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 2-33°. The Nb(2)-O(10) bond length is 2.01 Å. The Nb(2)-O(12) bond length is 1.86 Å. The Nb(2)-O(4) bond length is 1.99 Å. The Nb(2)-O(9) bond length is 2.25 Å. There is one shorter (2.04 Å) and one longer (2.07 Å) Nb(2)-O(2) bond length. In the third Nb site, Nb(3) is bonded to one O(10), one O(11), one O(3), one O(9), and two equivalent O(1) atoms to form NbO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, faces with two equivalent Sr(4)O12 cuboctahedra, and faces with four equivalent Sr(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 2-16°. The Nb(3)-O(10) bond length is 2.21 Å. The Nb(3)-O(11) bond length is 1.82 Å. The Nb(3)-O(3) bond length is 2.18 Å. The Nb(3)-O(9) bond length is 1.93 Å. There is one shorter (2.05 Å) and one longer (2.06 Å) Nb(3)-O(1) bond length. P(1) is bonded to one O(13), one O(3), one O(5), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Sr(3)O12 cuboctahedra,  a cornercorner with one Nb(3)O6 octahedra, and  an edgeedge with one Sr(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 51°. The P(1)-O(13) bond length is 1.53 Å. The P(1)-O(3) bond length is 1.62 Å. The P(1)-O(5) bond length is 1.55 Å. The P(1)-O(8) bond length is 1.56 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Sr(4), two equivalent Sr(3), and two equivalent Nb(3) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Sr(3), two equivalent Sr(4), and two equivalent Nb(2) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(3), one Nb(3), and one P(1) atom. In the fourth O site, O(4) is bonded to two equivalent Sr(4), one Nb(1), and one Nb(2) atom to form distorted OSr2Nb2 tetrahedra that share corners with three equivalent O(10)Sr4Nb2 octahedra,  a cornercorner with one O(7)Sr3Nb tetrahedra, corners with two equivalent O(4)Sr2Nb2 tetrahedra, and  an edgeedge with one O(10)Sr4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 8-18°. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Sr(2), two equivalent Sr(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 1-coordinate geometry to one Sr(1), two equivalent Sr(2), and one Nb(1) atom. In the seventh O site, O(7) is bonded to one Sr(1), two equivalent Sr(2), and one Nb(1) atom to form distorted OSr3Nb tetrahedra that share  a cornercorner with one O(4)Sr2Nb2 tetrahedra and corners with two equivalent O(7)Sr3Nb tetrahedra. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Sr(2), two equivalent Sr(1), and one P(1) atom. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to two equivalent Sr(3), two equivalent Sr(4), one Nb(2), and one Nb(3) atom. In the tenth O site, O(10) is bonded to two equivalent Sr(3), two equivalent Sr(4), one Nb(2), and one Nb(3) atom to form distorted OSr4Nb2 octahedra that share corners with three equivalent O(4)Sr2Nb2 tetrahedra, edges with two equivalent O(10)Sr4Nb2 octahedra, and  an edgeedge with one O(4)Sr2Nb2 tetrahedra. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to two equivalent Sr(1), two equivalent Sr(3), and one Nb(3) atom. In the twelfth O site, O(12) is bonded in a 1-coordinate geometry to two equivalent Sr(4), one Nb(1), and one Nb(2) atom. In the thirteenth O site, O(13) is bonded in a distorted single-bond geometry to one Sr(1), one Sr(3), and one P(1) atom. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Sr(2), one Sr(4), and two equivalent Nb(1) atoms.