DOE OSTI2020
CaSb2O4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to five O2- atoms to form distorted CaO5 trigonal bipyramids that share corners with three CaO6 octahedra and a cornercorner with one SbO5 square pyramid. The corner-sharing octahedra tilt angles range from 49–74°. There are a spread of Ca–O bond distances ranging from 2.35–2.76 Å. In the second Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.74 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with two equivalent CaO5 trigonal bipyramids and edges with two equivalent SbO5 square pyramids. There are a spread of Ca–O bond distances ranging from 2.33–2.47 Å. In the fourth Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted edge-sharing CaO6 pentagonal pyramids. There are a spread of Ca–O bond distances ranging from 2.33–2.47 Å. In the fifth Ca2+ site, Ca2+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Ca–O bond distances ranging from 2.23–2.26 Å. In the sixth Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share a cornercorner with one CaO5 trigonal bipyramid and an edgeedge with one CaO6 pentagonal pyramid. There are a spread of Ca–O bond distances ranging from 2.34–2.51 Å. There are twelve inequivalent Sb3+ sites. In the first Sb3+ site, Sb3+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Sb–O bond distances ranging from 2.03–2.40 Å. In the second Sb3+ site, Sb3+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of Sb–O bond distances ranging from 1.95–2.06 Å. In the third Sb3+ site, Sb3+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Sb–O bond distances ranging from 1.98–2.68 Å. In the fourth Sb3+ site, Sb3+ is bonded to five O2- atoms to form distorted SbO5 square pyramids that share a cornercorner with one CaO5 trigonal bipyramid and edges with two equivalent CaO6 octahedra. There are a spread of Sb–O bond distances ranging from 1.97–2.54 Å. In the fifth Sb3+ site, Sb3+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of Sb–O bond distances ranging from 1.93–2.03 Å. In the sixth Sb3+ site, Sb3+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Sb–O bond distances ranging from 1.98–2.06 Å. In the seventh Sb3+ site, Sb3+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of Sb–O bond distances ranging from 1.92–2.03 Å. In the eighth Sb3+ site, Sb3+ is bonded in a 3-coordinate geometry to three O2- atoms. There are one shorter (2.02 Å) and two longer (2.07 Å) Sb–O bond lengths. In the ninth Sb3+ site, Sb3+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of Sb–O bond distances ranging from 1.98–2.07 Å. In the tenth Sb3+ site, Sb3+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Sb–O bond distances ranging from 1.99–2.26 Å. In the eleventh Sb3+ site, Sb3+ is bonded in a distorted T-shaped geometry to three O2- atoms. There is one shorter (1.93 Å) and two longer (2.03 Å) Sb–O bond length. In the twelfth Sb3+ site, Sb3+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Sb–O bond distances ranging from 1.95–2.14 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ca2+ and one Sb3+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Sb3+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to two Ca2+ and two Sb3+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Sb3+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Ca2+ and one Sb3+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Sb3+ atoms. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two Sb3+ atoms. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Sb3+ atoms. In the ninth O2- site, O2- is bonded in a distorted T-shaped geometry to two Ca2+ and one Sb3+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ca2+ and two Sb3+ atoms. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Sb3+ atoms. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Sb3+ atoms. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and one Sb3+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Sb3+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ca2+ and one Sb3+ atom. In the sixteenth O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to two Ca2+ and two Sb3+ atoms. In the seventeenth O2- site, O2- is bonded in a 3-coordinate geometry to two Ca2+ and one Sb3+ atom. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Sb3+ atoms. In the nineteenth O2- site, O2- is bonded in a trigonal non-coplanar geometry to one Ca2+ and two Sb3+ atoms. In the twentieth O2- site, O2- is bonded in a distorted T-shaped geometry to two Ca2+ and one Sb3+ atom. In the twenty-first O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+ and two Sb3+ atoms. In the twenty-second O2- site, O2- is bonded in a trigonal planar geometry to one Ca2+ and two Sb3+ atoms. In the twenty-third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Sb3+ atoms. In the twenty-fourth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ca2+ and two Sb3+ atoms.