DOI: 10.17188/1281482
title: Materials Data on NaCa2TiSi2O8F by Materials Project

description: NaCa2TiSi2O8F crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.35–3.09 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with three CaO6 octahedra, corners with two TiO4 tetrahedra, corners with two SiO3F tetrahedra, edges with two equivalent NaO6 octahedra, and edges with two TiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 75–76°. There are a spread of Na–O bond distances ranging from 2.25–2.83 Å. In the third Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with three CaO6 octahedra, corners with two TiO4 tetrahedra, corners with two SiO3F tetrahedra, edges with two equivalent NaO6 octahedra, and edges with two TiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 74–76°. There are a spread of Na–O bond distances ranging from 2.27–2.83 Å. In the fourth Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.32–3.11 Å. There are eight inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six O2- and one F1- atom to form distorted CaO6F hexagonal pyramids that share a cornercorner with one TiO4 tetrahedra, a cornercorner with one SiO3F tetrahedra, corners with two SiO3F trigonal pyramids, edges with three CaO6 octahedra, and edges with two SiO3F trigonal pyramids. There are a spread of Ca–O bond distances ranging from 2.38–2.68 Å. The Ca–F bond length is 2.63 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share a cornercorner with one TiO4 tetrahedra, corners with five SiO3F tetrahedra, and edges with two CaO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.40–2.45 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two NaO6 octahedra, a cornercorner with one TiO4 tetrahedra, corners with four SiO3F tetrahedra, a cornercorner with one SiO3F trigonal pyramid, an edgeedge with one CaO6F hexagonal pyramid, and an edgeedge with one CaO6 octahedra. The corner-sharing octahedra tilt angles range from 74–75°. There are a spread of Ca–O bond distances ranging from 2.40–2.55 Å. In the fourth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to six O2- and one F1- atom. There are a spread of Ca–O bond distances ranging from 2.27–2.59 Å. The Ca–F bond length is 2.84 Å. In the fifth Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with two NaO6 octahedra, a cornercorner with one TiO4 tetrahedra, corners with five SiO3F tetrahedra, and edges with three CaO6 octahedra. The corner-sharing octahedral tilt angles are 76°. There are a spread of Ca–O bond distances ranging from 2.35–2.50 Å. In the sixth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to six O2- and one F1- atom. There are a spread of Ca–O bond distances ranging from 2.33–2.62 Å. The Ca–F bond length is 2.90 Å. In the seventh Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two NaO6 octahedra, a cornercorner with one TiO4 tetrahedra, corners with five SiO3F tetrahedra, and edges with three CaO6 octahedra. The corner-sharing octahedra tilt angles range from 75–76°. There are a spread of Ca–O bond distances ranging from 2.33–2.53 Å. In the eighth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share a cornercorner with one TiO4 tetrahedra, a cornercorner with one SiO3F tetrahedra, corners with four SiO3F trigonal pyramids, edges with two equivalent CaO6F hexagonal pyramids, and an edgeedge with one CaO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.27–2.50 Å. There are four inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to four O2- atoms to form TiO4 tetrahedra that share a cornercorner with one CaO6F hexagonal pyramid and corners with two SiO3F trigonal pyramids. There are a spread of Ti–O bond distances ranging from 1.77–1.90 Å. In the second Ti4+ site, Ti4+ is bonded to four O2- atoms to form TiO4 tetrahedra that share a cornercorner with one CaO6 octahedra, corners with two NaO6 octahedra, corners with two SiO3F tetrahedra, and edges with two NaO6 octahedra. The corner-sharing octahedra tilt angles range from 60–69°. There is two shorter (1.79 Å) and two longer (1.90 Å) Ti–O bond length. In the third Ti4+ site, Ti4+ is bonded to four O2- atoms to form TiO4 tetrahedra that share corners with two NaO6 octahedra, corners with two CaO6 octahedra, corners with two SiO3F tetrahedra, and edges with two NaO6 octahedra. The corner-sharing octahedra tilt angles range from 15–66°. There are a spread of Ti–O bond distances ranging from 1.78–1.92 Å. In the fourth Ti4+ site, Ti4+ is bonded to four O2- atoms to form TiO4 tetrahedra that share corners with two CaO6 octahedra and corners with two SiO3F tetrahedra. The corner-sharing octahedra tilt angles range from 7–69°. There are a spread of Ti–O bond distances ranging from 1.76–1.93 Å. There are eight inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to three O2- and one F1- atom to form SiO3F tetrahedra that share a cornercorner with one NaO6 octahedra, corners with three CaO6 octahedra, a cornercorner with one TiO4 tetrahedra, and a cornercorner with one SiO3F tetrahedra. The corner-sharing octahedra tilt angles range from 54–60°. There are a spread of Si–O bond distances ranging from 1.59–1.62 Å. The Si–F bond length is 1.83 Å. In the second Si4+ site, Si4+ is bonded to three O2- and one F1- atom to form SiO3F trigonal pyramids that share a cornercorner with one CaO6F hexagonal pyramid, corners with two equivalent CaO6 octahedra, a cornercorner with one TiO4 tetrahedra, a cornercorner with one SiO3F trigonal pyramid, and an edgeedge with one CaO6F hexagonal pyramid. The corner-sharing octahedra tilt angles range from 33–56°. There are a spread of Si–O bond distances ranging from 1.59–1.62 Å. The Si–F bond length is 1.80 Å. In the third Si4+ site, Si4+ is bonded to three O2- and one F1- atom to form SiO3F tetrahedra that share a cornercorner with one NaO6 octahedra, corners with four CaO6 octahedra, a cornercorner with one TiO4 tetrahedra, and a cornercorner with one SiO3F tetrahedra. The corner-sharing octahedra tilt angles range from 54–69°. There is two shorter (1.60 Å) and one longer (1.62 Å) Si–O bond length. The Si–F bond length is 1.80 Å. In the fourth Si4+ site, Si4+ is bonded to three O2- and one F1- atom to form SiO3F tetrahedra that share a cornercorner with one NaO6 octahedra, corners with five CaO6 octahedra, a cornercorner with one TiO4 tetrahedra, and a cornercorner with one SiO3F tetrahedra. The corner-sharing octahedra tilt angles range from 52–70°. There are a spread of Si–O bond distances ranging from 1.59–1.62 Å. The Si–F bond length is 1.81 Å. In the fifth Si4+ site, Si4+ is bonded to three O2- and one F1- atom to form SiO3F tetrahedra that share corners with three CaO6 octahedra, a cornercorner with one TiO4 tetrahedra, and a cornercorner with one SiO3F tetrahedra. The corner-sharing octahedra tilt angles range from 57–60°. There are a spread of Si–O bond distances ranging from 1.59–1.62 Å. The Si–F bond length is 1.83 Å. In the sixth Si4+ site, Si4+ is bonded to three O2- and one F1- atom to form SiO3F tetrahedra that share corners with three CaO6 octahedra, a cornercorner with one TiO4 tetrahedra, and a cornercorner with one SiO3F tetrahedra. The corner-sharing octahedra tilt angles range from 55–61°. There are a spread of Si–O bond distances ranging from 1.59–1.62 Å. The Si–F bond length is 1.83 Å. In the seventh Si4+ site, Si4+ is bonded to three O2- and one F1- atom to form SiO3F trigonal pyramids that share a cornercorner with one CaO6F hexagonal pyramid, corners with three CaO6 octahedra, a cornercorner with one TiO4 tetrahedra, a cornercorner with one SiO3F trigonal pyramid, and an edgeedge with one CaO6F hexagonal pyramid. The corner-sharing octahedra tilt angles range from 35–59°. There are a spread of Si–O bond distances ranging from 1.59–1.62 Å. The Si–F bond length is 1.79 Å. In the eighth Si4+ site, Si4+ is bonded to three O2- and one F1- atom to form SiO3F tetrahedra that share a cornercorner with one CaO6F hexagonal pyramid, a cornercorner with one NaO6 octahedra, corners with two equivalent CaO6 octahedra, a cornercorner with one TiO4 tetrahedra, and a cornercorner with one SiO3F tetrahedra. The corner-sharing octahedra tilt angles range from 52–62°. There is one shorter (1.59 Å) and two longer (1.61 Å) Si–O bond length. The Si–F bond length is 1.81 Å. There are thirty-two inequivalent O2- sites. In the first O2- site, O2- is bonded to two Na1+, one Ca2+, and one Ti4+ atom to form distorted corner-sharing ONa2CaTi tetrahedra. In the second O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Ca2+ and one Si4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ti4+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, one Ca2+, and one Ti4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ti4+, and one Si4+ atom. In the sixth O2- site, O2- is bonded to two Na1+, one Ca2+, and one Ti4+ atom to form distorted corner-sharing ONa2CaTi tetrahedra. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, two Ca2+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. In the ninth O2- site, O2- is bonded to two Na1+, one Ca2+, and one Ti4+ atom to form distorted corner-sharing ONa2CaTi tetrahedra. In the tenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Na1+, one Ti4+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Na1+, one Ti4+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, two Ca2+, and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ti4+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. In the sixteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Ti4+, and one Si4+ atom. In the seventeenth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ti4+, and one Si4+ atom. In the nineteenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Ca2+ and one Si4+ atom. In the twentieth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Ca2+ and one Si4+ atom. In the twenty-first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ca2+ and one Si4+ atom. In the twenty-second O2- site, O2- is bonded to two Na1+, one Ca2+, and one Ti4+ atom to form distorted corner-sharing ONa2CaTi tetrahedra. In the twenty-third O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one Si4+ atom. In the twenty-fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ca2+ and one Si4+ atom. In the twenty-fifth O2- site, O2- is bonded in a distorted linear geometry to two Na1+, one Ca2+, and one Ti4+ atom. In the twenty-sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ti4+, and one Si4+ atom. In the twenty-seventh O2- site, O2- is bonded in a 1-coordin