DOE OSTI2020
NdTa3O9 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are six inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded to twelve O2- atoms to form NdO12 cuboctahedra that share faces with two NdO12 cuboctahedra and faces with eight TaO6 octahedra. There are a spread of Nd–O bond distances ranging from 2.57–2.73 Å. In the second Nd3+ site, Nd3+ is bonded to twelve O2- atoms to form NdO12 cuboctahedra that share faces with two equivalent NdO12 cuboctahedra and faces with eight TaO6 octahedra. There are a spread of Nd–O bond distances ranging from 2.60–2.72 Å. In the third Nd3+ site, Nd3+ is bonded to twelve O2- atoms to form NdO12 cuboctahedra that share faces with two NdO12 cuboctahedra and faces with eight TaO6 octahedra. There are a spread of Nd–O bond distances ranging from 2.56–2.74 Å. In the fourth Nd3+ site, Nd3+ is bonded to twelve O2- atoms to form NdO12 cuboctahedra that share faces with two equivalent NdO12 cuboctahedra and faces with eight TaO6 octahedra. There are a spread of Nd–O bond distances ranging from 2.59–2.71 Å. In the fifth Nd3+ site, Nd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Nd–O bond distances ranging from 2.45–2.94 Å. In the sixth Nd3+ site, Nd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Nd–O bond distances ranging from 2.44–2.93 Å. There are sixteen 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 faces with two NdO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 11–43°. There are a spread of Ta–O bond distances ranging from 1.97–2.06 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with two equivalent NdO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 9–39°. There are a spread of Ta–O bond distances ranging from 1.92–2.04 Å. In the third Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with two NdO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 10–44°. There are a spread of Ta–O bond distances ranging from 1.92–2.03 Å. In the fourth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with two NdO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 10–39°. There are a spread of Ta–O bond distances ranging from 1.92–2.04 Å. In the fifth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with two equivalent NdO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 9–43°. There are a spread of Ta–O bond distances ranging from 1.92–2.04 Å. In the sixth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with two NdO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 11–44°. There are a spread of Ta–O bond distances ranging from 1.97–2.05 Å. In the seventh Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with two equivalent NdO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 9–43°. There are a spread of Ta–O bond distances ranging from 1.92–2.04 Å. In the eighth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with two NdO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 10–39°. There are a spread of Ta–O bond distances ranging from 1.92–2.04 Å. In the ninth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with two NdO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 11–44°. There are a spread of Ta–O bond distances ranging from 1.97–2.05 Å. In the tenth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with two equivalent NdO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 9–38°. There are a spread of Ta–O bond distances ranging from 1.92–2.03 Å. In the eleventh Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with two NdO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 11–43°. There are a spread of Ta–O bond distances ranging from 1.96–2.05 Å. In the twelfth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with two NdO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 10–44°. There are a spread of Ta–O bond distances ranging from 1.92–2.03 Å. In the thirteenth Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–42°. There are a spread of Ta–O bond distances ranging from 1.90–2.11 Å. In the fourteenth Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 6–39°. There is two shorter (1.95 Å) and four longer (2.02 Å) Ta–O bond length. In the fifteenth Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 6–39°. There is two shorter (1.95 Å) and four longer (2.02 Å) Ta–O bond length. In the sixteenth Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–42°. There are a spread of Ta–O bond distances ranging from 1.90–2.11 Å. There are forty-six inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to one Nd3+ and two Ta5+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to one Nd3+ and two Ta5+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the sixth O2- site, O2- is bonded in a distorted T-shaped geometry to one Nd3+ and two Ta5+ atoms. In the seventh O2- site, O2- is bonded in a distorted T-shaped geometry to one Nd3+ and two Ta5+ atoms. In the eighth O2- site, O2- is bonded in a distorted linear geometry to one Nd3+ and two Ta5+ atoms. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the tenth O2- site, O2- is bonded in a distorted T-shaped geometry to one Nd3+ and two Ta5+ atoms. In the eleventh O2- site, O2- is bonded in a distorted T-shaped geometry to one Nd3+ and two Ta5+ atoms. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted linear geometry to one Nd3+ and two Ta5+ atoms. In the fourteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta5+ atoms. In the fifteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the seventeenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta5+ atoms. In the eighteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the nineteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the twentieth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Nd3+ and two Ta5+ atoms. In the twenty-first O2- site, O2- is bonded in a distorted linear geometry to two Nd3+ and two Ta5+ atoms. In the twenty-second O2- site, O2- is bonded in a 2-coordinate geometry to two Nd3+ and two Ta5+ atoms. In the twenty-third O2- site, O2- is bonded in a distorted linear geometry to two equivalent Nd3+ and two Ta5+ atoms. In the twenty-fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Nd3+ and two Ta5+ atoms. In the twenty-fifth O2- site, O2- is bonded in a 2-coordinate geometry to two Nd3+ and two Ta5+ atoms. In the twenty-sixth O2- site, O2- is bonded in a 2-coordinate geometry to two Nd3+ and two Ta5+ atoms. In the twenty-seventh O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Nd3+ and two Ta5+ atoms. In the twenty-eighth O2- site, O2- is bonded in a 2-coordinate geometry to two Nd3+ and two Ta5+ atoms. In the twenty-ninth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Nd3+ and two Ta5+ atoms. In the thirtieth O2- site, O2- is bonded in a 2-coordinate geometry to two Nd3+ and two Ta5+ atoms. In the thirty-first O2- site, O2- is bonded in a distorted linear geometry to two Nd3+ and two Ta5+ atoms. In the thirty-second O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the thirty-third O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta5+ atoms. In the thirty-fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the thirty-fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta5+ atoms. In the thirty-sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the thirty-seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the thirty-eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the thirty-ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the fortieth O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta5+ atoms. In the forty-first O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the forty-second O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+ and two Ta5+ atoms. In the forty-third O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta5+ atoms. In the forty-fourth O2- site, O2- is bonded in a distorted T-shaped geometry to one Nd3+ and two Ta5+ atoms. In the forty-fifth O2- site, O2- is bonded in a linear geometry to two equivalent Ta5+ atoms. In the forty-sixth O2- site, O2- is bonded in a distorted T-shaped geometry to one Nd3+ and two Ta5+ atoms.