Ba3TaFe3Si2O14 is Esseneite-derived structured and crystallizes in the trigonal P321 space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(2) atoms. Ta(1) is bonded to six equivalent O(3) atoms to form TaO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra. Fe(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form FeO4 tetrahedra that share corners with two equivalent Ta(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 56°. Si(1) is bonded to one O(1) and three equivalent O(2) atoms to form SiO4 tetrahedra that share corners with three equivalent Fe(1)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Ba(1) and one Si(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ba(1), one Ta(1), and one Fe(1) atom.
Ba3TaFe3Si2O14 is Esseneite-derived structured and crystallizes in the trigonal P321 space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(2) atoms. Both Ba(1)-O(1) bond lengths are 2.81 Å. Both Ba(1)-O(3) bond lengths are 2.72 Å. There are two shorter (2.79 Å) and two longer (3.06 Å) Ba(1)-O(2) bond lengths. Ta(1) is bonded to six equivalent O(3) atoms to form TaO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra. All Ta(1)-O(3) bond lengths are 2.00 Å. Fe(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form FeO4 tetrahedra that share corners with two equivalent Ta(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 56°. Both Fe(1)-O(2) bond lengths are 1.93 Å. Both Fe(1)-O(3) bond lengths are 1.89 Å. Si(1) is bonded to one O(1) and three equivalent O(2) atoms to form SiO4 tetrahedra that share corners with three equivalent Fe(1)O4 tetrahedra. The Si(1)-O(1) bond length is 1.62 Å. All Si(1)-O(2) bond lengths are 1.66 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Ba(1) and one Si(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ba(1), one Ta(1), and one Fe(1) atom.