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DOE OSTI2020

Materials Data on Ta2H4O7 by Materials Project

H4OTa2O6 crystallizes in the monoclinic Cc space group. The structure is three-dimensional and consists of four water molecules and one HTaO3 framework. In the HTaO3 framework, there are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 33–49°. There are a spread of Ta–O bond distances ranging from 1.89–2.20 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 33–49°. There are a spread of Ta–O bond distances ranging from 1.91–2.15 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta5+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta5+ atoms. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Ta5+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Ta5+ atoms. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta5+ atoms. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to two Ta5+ and one H1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba9(TaN6)2 by Materials Project

Ba9(TaN6)2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are nine inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to seven N+2.33- atoms. There are a spread of Ba–N bond distances ranging from 2.82–3.32 Å. In the second Ba2+ site, Ba2+ is bonded to six N+2.33- atoms to form distorted BaN6 octahedra that share a cornercorner with one BaN6 octahedra, a cornercorner with one BaN5 square pyramid, a cornercorner with one TaN4 tetrahedra, a cornercorner with one BaN5 trigonal bipyramid, edges with three BaN6 octahedra, an edgeedge with one BaN5 square pyramid, an edgeedge with one TaN4 tetrahedra, and edges with two BaN5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 38°. There are a spread of Ba–N bond distances ranging from 2.54–3.17 Å. In the third Ba2+ site, Ba2+ is bonded to six N+2.33- atoms to form distorted BaN6 octahedra that share corners with two equivalent BaN6 octahedra, a cornercorner with one TaN4 tetrahedra, edges with two equivalent BaN6 octahedra, edges with two equivalent BaN5 square pyramids, an edgeedge with one TaN4 tetrahedra, and edges with two BaN5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 12–19°. There are a spread of Ba–N bond distances ranging from 2.76–3.13 Å. In the fourth Ba2+ site, Ba2+ is bonded to five N+2.33- atoms to form distorted BaN5 trigonal bipyramids that share corners with three equivalent BaN5 square pyramids, corners with four TaN4 tetrahedra, and edges with four BaN6 octahedra. There are a spread of Ba–N bond distances ranging from 2.67–3.21 Å. In the fifth Ba2+ site, Ba2+ is bonded in a 4-coordinate geometry to seven N+2.33- atoms. There are a spread of Ba–N bond distances ranging from 2.61–3.34 Å. In the sixth Ba2+ site, Ba2+ is bonded to six N+2.33- atoms to form distorted BaN6 octahedra that share corners with three BaN6 octahedra, a cornercorner with one BaN5 square pyramid, a cornercorner with one TaN4 tetrahedra, a cornercorner with one BaN5 trigonal bipyramid, edges with two BaN6 octahedra, an edgeedge with one BaN5 square pyramid, edges with two TaN4 tetrahedra, and edges with two equivalent BaN5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 12–38°. There are a spread of Ba–N bond distances ranging from 2.88–3.20 Å. In the seventh Ba2+ site, Ba2+ is bonded to five N+2.33- atoms to form distorted BaN5 trigonal bipyramids that share corners with two BaN6 octahedra, a cornercorner with one BaN5 square pyramid, corners with four TaN4 tetrahedra, edges with two BaN6 octahedra, and an edgeedge with one BaN5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 17–99°. There are a spread of Ba–N bond distances ranging from 2.70–3.08 Å. In the eighth Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to seven N+2.33- atoms. There are a spread of Ba–N bond distances ranging from 2.69–3.21 Å. In the ninth Ba2+ site, Ba2+ is bonded to five N+2.33- atoms to form distorted BaN5 square pyramids that share corners with two BaN6 octahedra, corners with two TaN4 tetrahedra, corners with four BaN5 trigonal bipyramids, edges with four BaN6 octahedra, an edgeedge with one BaN5 square pyramid, and an edgeedge with one TaN4 tetrahedra. The corner-sharing octahedra tilt angles range from 78–87°. There are a spread of Ba–N bond distances ranging from 2.72–3.23 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to four N+2.33- atoms to form TaN4 tetrahedra that share corners with three BaN6 octahedra, a cornercorner with one BaN5 square pyramid, corners with four BaN5 trigonal bipyramids, an edgeedge with one BaN6 octahedra, and an edgeedge with one BaN5 square pyramid. The corner-sharing octahedra tilt angles range from 55–84°. There are a spread of Ta–N bond distances ranging from 1.97–2.02 Å. In the second Ta5+ site, Ta5+ is bonded to four N+2.33- atoms to form TaN4 tetrahedra that share a cornercorner with one BaN5 square pyramid, corners with four BaN5 trigonal bipyramids, and edges with three BaN6 octahedra. There are a spread of Ta–N bond distances ranging from 1.95–2.00 Å. There are twelve inequivalent N+2.33- sites. In the first N+2.33- site, N+2.33- is bonded in a 1-coordinate geometry to four Ba2+ and one Ta5+ atom. In the second N+2.33- site, N+2.33- is bonded to five Ba2+ and one Ta5+ atom to form distorted NBa5Ta octahedra that share corners with two equivalent NBa6 octahedra and edges with three NBa5Ta octahedra. The corner-sharing octahedra tilt angles range from 20–24°. In the third N+2.33- site, N+2.33- is bonded in a 5-coordinate geometry to four Ba2+ and one N+2.33- atom. The N–N bond length is 1.19 Å. In the fourth N+2.33- site, N+2.33- is bonded in a distorted rectangular see-saw-like geometry to two Ba2+ and two N+2.33- atoms. The N–N bond length is 1.19 Å. In the fifth N+2.33- site, N+2.33- is bonded in a 5-coordinate geometry to four Ba2+ and one Ta5+ atom. In the sixth N+2.33- site, N+2.33- is bonded in a 6-coordinate geometry to five Ba2+ and one Ta5+ atom. In the seventh N+2.33- site, N+2.33- is bonded in a 6-coordinate geometry to four Ba2+ and one N+2.33- atom. In the eighth N+2.33- site, N+2.33- is bonded in a 6-coordinate geometry to five Ba2+ and one Ta5+ atom. In the ninth N+2.33- site, N+2.33- is bonded in a 6-coordinate geometry to five Ba2+ and one Ta5+ atom. In the tenth N+2.33- site, N+2.33- is bonded to six Ba2+ atoms to form a mixture of corner and edge-sharing NBa6 octahedra. The corner-sharing octahedra tilt angles range from 20–24°. In the eleventh N+2.33- site, N+2.33- is bonded in a 1-coordinate geometry to five Ba2+ and one Ta5+ atom. In the twelfth N+2.33- site, N+2.33- is bonded in a 1-coordinate geometry to five Ba2+ and one Ta5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbCa2Ta3O10 by Materials Project

RbCa2Ta3O10 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Rb1+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Rb–O bond lengths are 3.20 Å. Ca2+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of Ca–O bond distances ranging from 2.52–3.03 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ta–O bond lengths are 1.97 Å. In the second Ta5+ site, Ta5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ta–O bond distances ranging from 1.80–2.32 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to four equivalent Rb1+ and one Ta5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a linear geometry to four equivalent Ca2+ and two equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to four equivalent Ca2+ and two Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sc3TaO7 by Materials Project

Sc3TaO7 crystallizes in the monoclinic P2 space group. The structure is three-dimensional. there are three inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded in a 4-coordinate geometry to seven O2- atoms. There are a spread of Sc–O bond distances ranging from 1.93–2.56 Å. In the second Sc3+ site, Sc3+ is bonded to six O2- atoms to form distorted corner-sharing ScO6 octahedra. The corner-sharing octahedral tilt angles are 68°. There are a spread of Sc–O bond distances ranging from 2.11–2.16 Å. In the third Sc3+ site, Sc3+ is bonded in a 4-coordinate geometry to seven O2- atoms. There are a spread of Sc–O bond distances ranging from 1.93–2.59 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ta–O bond distances ranging from 2.11–2.17 Å. In the second Ta5+ site, Ta5+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ta–O bond distances ranging from 2.12–2.16 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two Sc3+ and two Ta5+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Sc3+ and one Ta5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two Sc3+ and two Ta5+ atoms. In the fourth O2- site, O2- is bonded to four Sc3+ atoms to form corner-sharing OSc4 tetrahedra. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three Sc3+ and one Ta5+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to three Sc3+ and one Ta5+ atom. In the seventh O2- site, O2- is bonded to four Sc3+ atoms to form corner-sharing OSc4 tetrahedra. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to three Sc3+ and one Ta5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Dy3TaO7 by Materials Project

Dy3TaO7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Dy3+ sites. In the first Dy3+ site, Dy3+ is bonded to six O2- atoms to form distorted corner-sharing DyO6 octahedra. The corner-sharing octahedra tilt angles range from 68–69°. There are a spread of Dy–O bond distances ranging from 2.26–2.30 Å. In the second Dy3+ site, Dy3+ is bonded to six O2- atoms to form distorted corner-sharing DyO6 octahedra. The corner-sharing octahedra tilt angles range from 68–69°. There are a spread of Dy–O bond distances ranging from 2.26–2.31 Å. In the third Dy3+ site, Dy3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Dy–O bond distances ranging from 2.08–2.55 Å. In the fourth Dy3+ site, Dy3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Dy–O bond distances ranging from 2.08–2.54 Å. In the fifth Dy3+ site, Dy3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Dy–O bond distances ranging from 2.09–2.50 Å. In the sixth Dy3+ site, Dy3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Dy–O bond distances ranging from 2.09–2.50 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Ta–O bond distances ranging from 2.00–2.50 Å. In the second Ta5+ site, Ta5+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Ta–O bond distances ranging from 2.00–2.49 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded to four Dy3+ atoms to form a mixture of corner and edge-sharing ODy4 tetrahedra. In the second O2- site, O2- is bonded to three Dy3+ and one Ta5+ atom to form distorted ODy3Ta tetrahedra that share corners with ten ODy4 tetrahedra and edges with three ODy3Ta tetrahedra. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two Dy3+ and two Ta5+ atoms. In the fourth O2- site, O2- is bonded to three Dy3+ and one Ta5+ atom to form distorted ODy3Ta tetrahedra that share corners with ten ODy4 tetrahedra and edges with three ODy3Ta tetrahedra. In the fifth O2- site, O2- is bonded to three Dy3+ and one Ta5+ atom to form distorted ODy3Ta tetrahedra that share corners with ten ODy3Ta tetrahedra and edges with three ODy4 tetrahedra. In the sixth O2- site, O2- is bonded to three Dy3+ and one Ta5+ atom to form distorted ODy3Ta tetrahedra that share corners with ten ODy4 tetrahedra and edges with three ODy3Ta tetrahedra. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two Dy3+ and two Ta5+ atoms. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Dy3+ and two Ta5+ atoms. In the ninth O2- site, O2- is bonded to three Dy3+ and one Ta5+ atom to form distorted ODy3Ta tetrahedra that share corners with ten ODy3Ta tetrahedra and edges with three ODy4 tetrahedra. In the tenth O2- site, O2- is bonded to three Dy3+ and one Ta5+ atom to form distorted ODy3Ta tetrahedra that share corners with ten ODy3Ta tetrahedra and edges with three ODy4 tetrahedra. In the eleventh O2- site, O2- is bonded to three Dy3+ and one Ta5+ atom to form distorted ODy3Ta tetrahedra that share corners with ten ODy4 tetrahedra and edges with three ODy3Ta tetrahedra. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to two Dy3+ and two Ta5+ atoms. In the thirteenth O2- site, O2- is bonded to three Dy3+ and one Ta5+ atom to form distorted ODy3Ta tetrahedra that share corners with ten ODy3Ta tetrahedra and edges with three ODy4 tetrahedra. In the fourteenth O2- site, O2- is bonded to four Dy3+ atoms to form ODy4 tetrahedra that share corners with ten ODy4 tetrahedra and edges with four ODy3Ta tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TaHg2F6 by Materials Project

TaHg2F6 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Ta3+ is bonded in an octahedral geometry to six F1- atoms. There are a spread of Ta–F bond distances ranging from 1.92–1.94 Å. There are two inequivalent Hg+1.50+ sites. In the first Hg+1.50+ site, Hg+1.50+ is bonded in a distorted rectangular see-saw-like geometry to four F1- atoms. There are two shorter (2.92 Å) and two longer (2.99 Å) Hg–F bond lengths. In the second Hg+1.50+ site, Hg+1.50+ is bonded in a 6-coordinate geometry to four F1- atoms. There are two shorter (2.88 Å) and two longer (2.97 Å) Hg–F bond lengths. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to one Ta3+ and two Hg+1.50+ atoms. In the second F1- site, F1- is bonded in a distorted single-bond geometry to one Ta3+ and two equivalent Hg+1.50+ atoms. In the third F1- site, F1- is bonded in a single-bond geometry to one Ta3+ atom. In the fourth F1- site, F1- is bonded in a distorted single-bond geometry to one Ta3+ and two equivalent Hg+1.50+ atoms. In the fifth F1- site, F1- is bonded in a distorted single-bond geometry to one Ta3+ and two equivalent Hg+1.50+ atoms. The F–Ta bond length is 1.92 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on UTa2O7 by Materials Project

UTa2O7 crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. U4+ is bonded to eight O2- atoms to form distorted UO8 hexagonal bipyramids that share edges with two equivalent UO8 hexagonal bipyramids and edges with six TaO6 octahedra. There are a spread of U–O bond distances ranging from 2.08–2.66 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and edges with two equivalent UO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 35–44°. There is two shorter (1.96 Å) and four longer (2.02 Å) Ta–O bond length. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and edges with four equivalent UO8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 44°. All Ta–O bond lengths are 1.99 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one U4+ and two Ta5+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent U4+ and two equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent U4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y3TaO7 by Materials Project

Y3TaO7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Y–O bond distances ranging from 2.15–2.80 Å. In the second Y3+ site, Y3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Y–O bond distances ranging from 2.17–2.71 Å. In the third Y3+ site, Y3+ is bonded to six O2- atoms to form YO6 octahedra that share corners with two equivalent YO6 octahedra and corners with two TaO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 64°. There are a spread of Y–O bond distances ranging from 2.19–2.39 Å. In the fourth Y3+ site, Y3+ is bonded in a 5-coordinate geometry to six O2- atoms. There are a spread of Y–O bond distances ranging from 2.16–2.82 Å. In the fifth Y3+ site, Y3+ is bonded to six O2- atoms to form YO6 octahedra that share corners with two equivalent YO6 octahedra and corners with two TaO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 64°. There are a spread of Y–O bond distances ranging from 2.17–2.41 Å. In the sixth Y3+ site, Y3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Y–O bond distances ranging from 2.18–2.65 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to five O2- atoms to form distorted TaO5 trigonal bipyramids that share corners with two YO6 octahedra and corners with two equivalent TaO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 58–65°. There are a spread of Ta–O bond distances ranging from 1.88–2.27 Å. In the second Ta5+ site, Ta5+ is bonded to five O2- atoms to form distorted TaO5 trigonal bipyramids that share corners with two YO6 octahedra and corners with two equivalent TaO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 60–64°. There are a spread of Ta–O bond distances ranging from 1.88–2.32 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Y3+ and one Ta5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to four Y3+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to three Y3+ and one Ta5+ atom. In the fourth O2- site, O2- is bonded to four Y3+ atoms to form distorted corner-sharing OY4 tetrahedra. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to four Y3+ atoms. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Y3+ atoms. In the seventh O2- site, O2- is bonded to four Y3+ atoms to form distorted corner-sharing OY4 tetrahedra. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Y3+ and two Ta5+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Y3+ atoms. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Y3+ and one Ta5+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Y3+ and two Ta5+ atoms. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Y3+ and one Ta5+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Y3+ and one Ta5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Y3+ and one Ta5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr6Ta2O11 by Materials Project

Sr6Ta2O11 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.64–3.10 Å. In the second Sr2+ site, Sr2+ is bonded to five O2- atoms to form distorted SrO5 square pyramids that share corners with four equivalent TaO6 octahedra and a cornercorner with one TaO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 10°. There are four shorter (2.30 Å) and one longer (2.85 Å) Sr–O bond lengths. In the third Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are two shorter (2.32 Å) and four longer (2.57 Å) Sr–O bond lengths. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to five O2- atoms to form distorted TaO5 trigonal bipyramids that share a cornercorner with one SrO5 square pyramid. There is one shorter (1.91 Å) and four longer (1.97 Å) Ta–O bond length. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four equivalent SrO5 square pyramids. There is two shorter (1.95 Å) and four longer (2.01 Å) Ta–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to five Sr2+ and one Ta5+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to five Sr2+ and one Ta5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Sr2+ and one Ta5+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to five Sr2+ and one Ta5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ta2O5 by Materials Project

Ta2O5 crystallizes in the monoclinic Cm space group. The structure is two-dimensional and consists of two Ta2O5 sheets oriented in the (1, 0, 0) direction. there are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ta–O bond distances ranging from 1.73–2.15 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form edge-sharing TaO6 octahedra. There are a spread of Ta–O bond distances ranging from 1.96–2.08 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three Ta5+ atoms. In the second O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Ta5+ atoms. In the third O2- site, O2- is bonded in a water-like geometry to two equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Ta5+ atoms. In the fifth O2- site, O2- is bonded in a single-bond geometry to one Ta5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr6La2Ta3Al5O24 by Materials Project

Sr6La2Ta3Al5O24 is (Cubic) Perovskite-derived structured and crystallizes in the trigonal R32 space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with three equivalent LaO12 cuboctahedra, corners with nine SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four AlO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.76–2.80 Å. In the second Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with three equivalent LaO12 cuboctahedra, corners with nine SrO12 cuboctahedra, faces with three equivalent SrO12 cuboctahedra, faces with three equivalent LaO12 cuboctahedra, faces with three equivalent TaO6 octahedra, and faces with five AlO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.72–2.86 Å. In the third Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four equivalent AlO6 octahedra. There are nine shorter (2.76 Å) and three longer (2.77 Å) Sr–O bond lengths. La3+ is bonded to twelve O2- atoms to form LaO12 cuboctahedra that share corners with six SrO12 cuboctahedra, corners with six equivalent LaO12 cuboctahedra, faces with three equivalent SrO12 cuboctahedra, faces with three equivalent LaO12 cuboctahedra, a faceface with one TaO6 octahedra, and faces with seven AlO6 octahedra. There are a spread of La–O bond distances ranging from 2.60–2.82 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six AlO6 octahedra, a faceface with one LaO12 cuboctahedra, and faces with seven SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There is three shorter (1.99 Å) and three longer (2.00 Å) Ta–O bond length. In the second Ta5+ site, Ta5+ is bonded to six equivalent O2- atoms to form TaO6 octahedra that share corners with six equivalent AlO6 octahedra and faces with eight SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Ta–O bond lengths are 1.99 Å. There are three inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six equivalent O2- atoms to form AlO6 octahedra that share corners with six equivalent AlO6 octahedra, faces with two equivalent SrO12 cuboctahedra, and faces with six equivalent LaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 2°. All Al–O bond lengths are 1.94 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with three equivalent TaO6 octahedra, corners with three equivalent AlO6 octahedra, faces with four SrO12 cuboctahedra, and faces with four equivalent LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 1–2°. All Al–O bond lengths are 1.93 Å. In the third Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six TaO6 octahedra and faces with eight SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Al–O bond lengths are 1.92 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to one Sr2+, three equivalent La3+, and two Al3+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to three Sr2+, one La3+, one Ta5+, and one Al3+ atom. In the third O2- site, O2- is bonded in a distorted linear geometry to four Sr2+, one Ta5+, and one Al3+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to four Sr2+, one Ta5+, and one Al3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho3TaO7 by Materials Project

Ho3TaO7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded to six O2- atoms to form distorted HoO6 octahedra that share corners with two equivalent HoO6 octahedra and corners with two TaO4 tetrahedra. The corner-sharing octahedral tilt angles are 64°. There are a spread of Ho–O bond distances ranging from 2.16–2.40 Å. In the second Ho3+ site, Ho3+ is bonded to six O2- atoms to form distorted HoO6 octahedra that share corners with two equivalent HoO6 octahedra and corners with two TaO4 tetrahedra. The corner-sharing octahedral tilt angles are 64°. There are a spread of Ho–O bond distances ranging from 2.17–2.41 Å. In the third Ho3+ site, Ho3+ is bonded in a 5-coordinate geometry to six O2- atoms. There are a spread of Ho–O bond distances ranging from 2.15–2.72 Å. In the fourth Ho3+ site, Ho3+ is bonded in a 5-coordinate geometry to seven O2- atoms. There are a spread of Ho–O bond distances ranging from 2.15–2.80 Å. In the fifth Ho3+ site, Ho3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ho–O bond distances ranging from 2.13–2.71 Å. In the sixth Ho3+ site, Ho3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ho–O bond distances ranging from 2.13–2.68 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to four O2- atoms to form distorted TaO4 tetrahedra that share corners with two HoO6 octahedra and a cornercorner with one TaO5 tetrahedra. The corner-sharing octahedra tilt angles range from 60–63°. There is two shorter (1.90 Å) and two longer (1.91 Å) Ta–O bond length. In the second Ta5+ site, Ta5+ is bonded to five O2- atoms to form distorted TaO5 tetrahedra that share corners with two HoO6 octahedra and a cornercorner with one TaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 61–63°. There are a spread of Ta–O bond distances ranging from 1.90–2.47 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded to four Ho3+ atoms to form corner-sharing OHo4 tetrahedra. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ho3+ atoms. In the third O2- site, O2- is bonded to four Ho3+ atoms to form corner-sharing OHo4 tetrahedra. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Ho3+ and one Ta5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one Ta5+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one Ta5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ho3+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and one Ta5+ atom. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to one Ho3+ and two Ta5+ atoms. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to three Ho3+ atoms. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one Ta5+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one Ta5+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and one Ta5+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to three Ho3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K4BaTa6(Si2O13)2 by Materials Project

K4BaTa6(Si2O13)2 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 4-coordinate geometry to fifteen O2- atoms. There are a spread of K–O bond distances ranging from 2.73–3.33 Å. In the second K1+ site, K1+ is bonded in a 6-coordinate geometry to thirteen O2- atoms. There are a spread of K–O bond distances ranging from 2.90–3.30 Å. Ba2+ is bonded in a 6-coordinate geometry to thirteen O2- atoms. There are a spread of Ba–O bond distances ranging from 2.90–3.28 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 2–32°. There are a spread of Ta–O bond distances ranging from 1.97–2.05 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 2–32°. There are a spread of Ta–O bond distances ranging from 1.96–2.06 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three TaO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 23–26°. There is one shorter (1.62 Å) and three longer (1.63 Å) Si–O bond length. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two K1+, one Ba2+, one Ta5+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two K1+, one Ba2+, one Ta5+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted linear geometry to two equivalent K1+ and two equivalent Si4+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+ and two Ta5+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to four K1+, one Ta5+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a linear geometry to two equivalent K1+, one Ba2+, and two equivalent Ta5+ atoms. In the seventh O2- site, O2- is bonded in a distorted linear geometry to two equivalent K1+ and two equivalent Ta5+ atoms. In the eighth O2- site, O2- is bonded in a linear geometry to two equivalent K1+ and two equivalent Ta5+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ba2+ and two equivalent Ta5+ atoms. In the tenth O2- site, O2- is bonded in a linear geometry to two equivalent K1+, one Ba2+, and two equivalent Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba3LiTa3Ti5O21 by Materials Project

Ba3LiTa3Ti5O21 is Orthorhombic Perovskite-derived structured and crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. Li1+ is bonded in a distorted trigonal planar geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.87–2.63 Å. There are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of Ba–O bond distances ranging from 2.77–3.26 Å. In the second Ba2+ site, Ba2+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of Ba–O bond distances ranging from 2.75–3.22 Å. There are three inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with three TaO6 octahedra, and edges with two equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 27–41°. There are a spread of Ti–O bond distances ranging from 1.89–2.17 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with three TiO6 octahedra, an edgeedge with one TiO6 octahedra, and an edgeedge with one TaO6 octahedra. The corner-sharing octahedra tilt angles range from 26–42°. There are a spread of Ti–O bond distances ranging from 1.89–2.18 Å. In the third Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two TiO6 octahedra, corners with three TaO6 octahedra, and edges with two TiO6 octahedra. The corner-sharing octahedra tilt angles range from 26–42°. There are a spread of Ti–O bond distances ranging from 1.87–2.19 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with three TiO6 octahedra, and edges with two equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 27–43°. There are a spread of Ta–O bond distances ranging from 1.96–2.06 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share a cornercorner with one TaO6 octahedra and corners with five TiO6 octahedra. The corner-sharing octahedra tilt angles range from 37–43°. There are a spread of Ta–O bond distances ranging from 1.97–2.02 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one Ti4+, and one Ta5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and three Ti4+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, two Ba2+, and two Ti4+ atoms. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to one Li1+, one Ba2+, two equivalent Ti4+, and one Ta5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, two equivalent Ba2+, one Ti4+, and one Ta5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two Ba2+, one Ti4+, and one Ta5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Ba2+, one Ti4+, and one Ta5+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+, two Ti4+, and one Ta5+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and three Ti4+ atoms. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to two Ba2+ and two Ta5+ atoms. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to two Ba2+, one Ti4+, and one Ta5+ atom. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one Ti4+, and one Ta5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TaTe4 by Materials Project

TaTe4 crystallizes in the tetragonal P4/ncc space group. The structure is one-dimensional and consists of four TaTe4 ribbons oriented in the (0, 0, 1) direction. there are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded in a 8-coordinate geometry to eight Te+1.25- atoms. There are a spread of Ta–Te bond distances ranging from 2.82–3.00 Å. In the second Ta5+ site, Ta5+ is bonded in a 8-coordinate geometry to eight Te+1.25- atoms. There are four shorter (2.91 Å) and four longer (2.93 Å) Ta–Te bond lengths. There are three inequivalent Te+1.25- sites. In the first Te+1.25- site, Te+1.25- is bonded in a 3-coordinate geometry to two Ta5+ atoms. In the second Te+1.25- site, Te+1.25- is bonded in a 2-coordinate geometry to two equivalent Ta5+ atoms. In the third Te+1.25- site, Te+1.25- is bonded in a 3-coordinate geometry to two Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K3Ta2AsSe11 by Materials Project

K3Ta2AsSe11 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to nine Se+1.45- atoms. There are a spread of K–Se bond distances ranging from 3.39–3.72 Å. In the second K1+ site, K1+ is bonded in a 10-coordinate geometry to ten Se+1.45- atoms. There are a spread of K–Se bond distances ranging from 3.45–4.04 Å. In the third K1+ site, K1+ is bonded in a 10-coordinate geometry to ten Se+1.45- atoms. There are a spread of K–Se bond distances ranging from 3.32–4.07 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to seven Se+1.45- atoms to form distorted face-sharing TaSe7 pentagonal bipyramids. There are a spread of Ta–Se bond distances ranging from 2.37–2.93 Å. In the second Ta5+ site, Ta5+ is bonded to seven Se+1.45- atoms to form distorted face-sharing TaSe7 pentagonal bipyramids. There are a spread of Ta–Se bond distances ranging from 2.37–2.88 Å. As3+ is bonded in a distorted trigonal non-coplanar geometry to three Se+1.45- atoms. There are a spread of As–Se bond distances ranging from 2.41–2.48 Å. There are eleven inequivalent Se+1.45- sites. In the first Se+1.45- site, Se+1.45- is bonded in a 1-coordinate geometry to two K1+, one Ta5+, and one Se+1.45- atom. The Se–Se bond length is 2.39 Å. In the second Se+1.45- site, Se+1.45- is bonded in a distorted L-shaped geometry to three K1+, one Ta5+, and one As3+ atom. In the third Se+1.45- site, Se+1.45- is bonded in a 2-coordinate geometry to four K1+ and two Ta5+ atoms. In the fourth Se+1.45- site, Se+1.45- is bonded in a 1-coordinate geometry to three K1+ and one Ta5+ atom. In the fifth Se+1.45- site, Se+1.45- is bonded in a 4-coordinate geometry to two equivalent K1+, one Ta5+, and one As3+ atom. In the sixth Se+1.45- site, Se+1.45- is bonded in a 2-coordinate geometry to two K1+, one Ta5+, and one Se+1.45- atom. The Se–Se bond length is 2.41 Å. In the seventh Se+1.45- site, Se+1.45- is bonded in a 2-coordinate geometry to two K1+, two Ta5+, and one Se+1.45- atom. In the eighth Se+1.45- site, Se+1.45- is bonded in a 1-coordinate geometry to four K1+ and one Ta5+ atom. In the ninth Se+1.45- site, Se+1.45- is bonded in an L-shaped geometry to one K1+, one Ta5+, and one As3+ atom. In the tenth Se+1.45- site, Se+1.45- is bonded in a distorted single-bond geometry to four K1+ and one Ta5+ atom. In the eleventh Se+1.45- site, Se+1.45- is bonded in a 2-coordinate geometry to two K1+, two Ta5+, and one Se+1.45- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TaO2 by Materials Project

TaO2 crystallizes in the tetragonal I4_1/a space group. The structure is one-dimensional and consists of four TaO2 ribbons oriented in the (0, 0, 1) direction. there are two inequivalent Ta4+ sites. In the first Ta4+ site, Ta4+ is bonded in a distorted pentagonal planar geometry to five O2- atoms. There are a spread of Ta–O bond distances ranging from 1.88–2.20 Å. In the second Ta4+ site, Ta4+ is bonded to five O2- atoms to form distorted corner-sharing TaO5 square pyramids. There are a spread of Ta–O bond distances ranging from 1.93–2.11 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three Ta4+ atoms. In the second O2- site, O2- is bonded in a water-like geometry to two Ta4+ atoms. In the third O2- site, O2- is bonded in an L-shaped geometry to two Ta4+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Ta4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ta2Mn4O9 by Materials Project

Mn4Ta2O9 is Ilmenite-like structured and crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with three equivalent TaO6 octahedra, corners with three equivalent MnO6 octahedra, corners with two equivalent MnO6 pentagonal pyramids, and a faceface with one MnO6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 38–46°. There are a spread of Ta–O bond distances ranging from 1.90–2.25 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with three equivalent TaO6 octahedra, corners with three equivalent MnO6 octahedra, a cornercorner with one MnO6 pentagonal pyramid, and an edgeedge with one MnO6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 38–42°. There are a spread of Ta–O bond distances ranging from 1.90–2.21 Å. There are four inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six TaO6 octahedra and edges with two equivalent MnO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 38–46°. There are a spread of Mn–O bond distances ranging from 2.13–2.29 Å. In the second Mn2+ site, Mn2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Mn–O bond distances ranging from 2.11–2.46 Å. In the third Mn2+ site, Mn2+ is bonded to six O2- atoms to form distorted MnO6 pentagonal pyramids that share corners with three TaO6 octahedra, an edgeedge with one TaO6 octahedra, edges with two equivalent MnO6 octahedra, and a faceface with one TaO6 octahedra. The corner-sharing octahedra tilt angles range from 59–65°. There are a spread of Mn–O bond distances ranging from 2.15–2.38 Å. In the fourth Mn2+ site, Mn2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Mn–O bond distances ranging from 2.14–2.43 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ta5+ and three Mn2+ atoms to form a mixture of distorted corner and edge-sharing OTaMn3 trigonal pyramids. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Ta5+ and three Mn2+ atoms. In the third O2- site, O2- is bonded to one Ta5+ and three Mn2+ atoms to form distorted corner-sharing OTaMn3 trigonal pyramids. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two Ta5+ and two Mn2+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Ta5+ and two Mn2+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Ta5+ and three Mn2+ atoms. In the seventh O2- site, O2- is bonded in a distorted see-saw-like geometry to one Ta5+ and three Mn2+ atoms. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Ta5+ and two Mn2+ atoms. In the ninth O2- site, O2- is bonded to one Ta5+ and three Mn2+ atoms to form a mixture of distorted corner and edge-sharing OTaMn3 trigonal pyramids.

36 MATERIALS SCIENCE↗