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DOE OSTI2020

Materials Data on Na3Mg2P5O16 by Materials Project

Na3Mg2P5O16 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.35–2.48 Å. In the second Na1+ site, Na1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are two shorter (2.38 Å) and two longer (2.55 Å) Na–O bond lengths. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 2.06–2.22 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent MgO6 octahedra and corners with two equivalent PO4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. There is two shorter (1.50 Å) and two longer (1.61 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent MgO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–46°. There are a spread of P–O bond distances ranging from 1.51–1.61 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent MgO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–48°. There are a spread of P–O bond distances ranging from 1.52–1.68 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mg2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Mg2+, and one P5+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two P5+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mg2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mg2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mg2+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Mg2+, and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaMg4(PO4)3 by Materials Project

NaMg4(PO4)3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Na1+ is bonded to six O2- atoms to form distorted NaO6 pentagonal pyramids that share corners with two equivalent MgO5 square pyramids, corners with two equivalent PO4 tetrahedra, corners with two equivalent MgO5 trigonal bipyramids, and edges with two PO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.52–2.73 Å. There are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five O2- atoms to form distorted MgO5 square pyramids that share a cornercorner with one NaO6 pentagonal pyramid, corners with five PO4 tetrahedra, a cornercorner with one MgO5 trigonal bipyramid, and edges with two equivalent MgO5 square pyramids. There are a spread of Mg–O bond distances ranging from 1.99–2.15 Å. In the second Mg2+ site, Mg2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Mg–O bond distances ranging from 1.98–2.63 Å. In the third Mg2+ site, Mg2+ is bonded to five O2- atoms to form distorted MgO5 trigonal bipyramids that share corners with two equivalent NaO6 pentagonal pyramids, corners with two equivalent MgO5 square pyramids, and corners with five PO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 1.99–2.20 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent NaO6 pentagonal pyramids, corners with two equivalent MgO5 square pyramids, and corners with two equivalent MgO5 trigonal bipyramids. There is three shorter (1.55 Å) and one longer (1.57 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent MgO5 square pyramids, corners with three equivalent MgO5 trigonal bipyramids, and an edgeedge with one NaO6 pentagonal pyramid. There are a spread of P–O bond distances ranging from 1.52–1.60 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent MgO5 square pyramids and an edgeedge with one NaO6 pentagonal pyramid. There are a spread of P–O bond distances ranging from 1.52–1.60 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+, one Mg2+, and one P5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Mg2+, and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Mg2+ and one P5+ atom. In the fourth O2- site, O2- is bonded to three Mg2+ and one P5+ atom to form edge-sharing OMg3P tetrahedra. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Mg2+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Mg2+, and one P5+ atom. In the seventh O2- site, O2- is bonded to three Mg2+ and one P5+ atom to form edge-sharing OMg3P tetrahedra. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to three Mg2+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to two Mg2+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2Mg5(PO4)4 by Materials Project

Na2Mg5(PO4)4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.43–2.88 Å. There are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with four PO4 tetrahedra, an edgeedge with one MgO6 octahedra, an edgeedge with one PO4 tetrahedra, and edges with two equivalent MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.01–2.30 Å. In the second Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share corners with five PO4 tetrahedra and edges with two equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 1.93–2.09 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six PO4 tetrahedra and edges with two equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.06–2.24 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two MgO6 octahedra, corners with three equivalent MgO5 trigonal bipyramids, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 44–53°. There are a spread of P–O bond distances ranging from 1.51–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with five MgO6 octahedra and corners with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 39–54°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mg2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two Mg2+, and one P5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Mg2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two Mg2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, two Mg2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Mg2+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a linear geometry to one Mg2+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaMgPO4 by Materials Project

NaMgPO4 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.30–2.70 Å. In the second Na1+ site, Na1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Na–O bond distances ranging from 2.33–3.00 Å. In the third Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.33–2.77 Å. There are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share corners with five PO4 tetrahedra and corners with two equivalent MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 1.99–2.22 Å. In the second Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share a cornercorner with one MgO6 octahedra, corners with five PO4 tetrahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedral tilt angles are 68°. There are a spread of Mg–O bond distances ranging from 1.98–2.17 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with six PO4 tetrahedra, a cornercorner with one MgO5 trigonal bipyramid, and an edgeedge with one MgO5 trigonal bipyramid. There are a spread of Mg–O bond distances ranging from 2.05–2.58 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent MgO6 octahedra and corners with three MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 39–50°. There is three shorter (1.55 Å) and one longer (1.58 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent MgO6 octahedra and corners with four MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 41–50°. There are a spread of P–O bond distances ranging from 1.54–1.58 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent MgO6 octahedra and corners with three MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 43–51°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to two Na1+, two Mg2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Mg2+, and one P5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+, one Mg2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Mg2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to two Na1+, two Mg2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Na1+, one Mg2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Mg2+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 5-coordinate geometry to two Na1+, two equivalent Mg2+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Mg2+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a 5-coordinate geometry to two Na1+, two Mg2+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to three Na1+, one Mg2+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Mg2+, and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na4Mg3P4O15 by Materials Project

Na4Mg3(PO4)2(P2O7) crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.34–2.84 Å. In the second 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 2.43–2.61 Å. In the third Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.33–2.60 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 2.37–3.05 Å. There are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with four PO4 tetrahedra and an edgeedge with one PO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 2.08–2.19 Å. In the second Mg2+ site, Mg2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Mg–O bond distances ranging from 2.04–2.64 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with four PO4 tetrahedra and an edgeedge with one PO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 2.06–2.26 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent MgO6 octahedra and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 41–47°. There are a spread of P–O bond distances ranging from 1.54–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent MgO6 octahedra and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 42–46°. There are a spread of P–O bond distances ranging from 1.53–1.57 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two MgO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–52°. There are a spread of P–O bond distances ranging from 1.52–1.64 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two MgO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of P–O bond distances ranging from 1.52–1.66 Å. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Mg2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Mg2+, and one P5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Mg2+, and one P5+ atom. In the fourth O2- site, O2- is bonded to two Na1+, one Mg2+, and one P5+ atom to form distorted corner-sharing ONa2MgP tetrahedra. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Mg2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Mg2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Mg2+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Mg2+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Mg2+, and one P5+ atom. In the tenth O2- site, O2- is bonded to one Na1+, two Mg2+, and one P5+ atom to form distorted corner-sharing ONaMg2P tetrahedra. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Mg2+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Na1+ and two P5+ atoms. In the thirteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, two Mg2+, and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na1+, one Mg2+, and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na14Mg9(P2O7)8 by Materials Project

Na14Mg9(P2O7)8 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are seven inequivalent Na sites. In the first Na site, Na is bonded in a 6-coordinate geometry to eight O atoms. There are a spread of Na–O bond distances ranging from 2.39–2.99 Å. In the second Na site, Na is bonded in a 2-coordinate geometry to eight O atoms. There are a spread of Na–O bond distances ranging from 2.30–2.93 Å. In the third Na site, Na is bonded in a distorted see-saw-like geometry to four O atoms. There are a spread of Na–O bond distances ranging from 2.29–2.48 Å. In the fourth Na site, Na is bonded in a 4-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.30–2.94 Å. In the fifth Na site, Na is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Na–O bond distances ranging from 2.30–2.78 Å. In the sixth Na site, Na is bonded to six O atoms to form distorted NaO6 octahedra that share corners with six PO4 tetrahedra and edges with two MgO6 octahedra. There are a spread of Na–O bond distances ranging from 2.30–2.69 Å. In the seventh Na site, Na is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.27–2.49 Å. There are five inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share a cornercorner with one MgO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. There are a spread of Mg–O bond distances ranging from 2.00–2.27 Å. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share a cornercorner with one MgO6 octahedra, corners with four PO4 tetrahedra, an edgeedge with one NaO6 octahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 63°. There are a spread of Mg–O bond distances ranging from 1.99–2.26 Å. In the third Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share a cornercorner with one MgO6 octahedra and corners with six PO4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. There are a spread of Mg–O bond distances ranging from 2.03–2.27 Å. In the fourth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share a cornercorner with one MgO6 octahedra, corners with six PO4 tetrahedra, and an edgeedge with one NaO6 octahedra. The corner-sharing octahedral tilt angles are 63°. There are a spread of Mg–O bond distances ranging from 2.05–2.20 Å. In the fifth Mg site, Mg is bonded in a 4-coordinate geometry to six O atoms. There are a spread of Mg–O bond distances ranging from 2.06–2.69 Å. There are eight inequivalent P sites. In the first P site, P is bonded to four O atoms to form PO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two MgO6 octahedra, a cornercorner with one PO4 tetrahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 48–54°. There are a spread of P–O bond distances ranging from 1.52–1.61 Å. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two MgO6 octahedra, a cornercorner with one PO4 tetrahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 49–63°. There are a spread of P–O bond distances ranging from 1.52–1.61 Å. In the third P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with three MgO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–50°. There are a spread of P–O bond distances ranging from 1.52–1.63 Å. In the fourth P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with two equivalent NaO6 octahedra, corners with three MgO6 octahedra, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 39–65°. There are a spread of P–O bond distances ranging from 1.52–1.63 Å. In the fifth P site, P is bonded to four O atoms to form PO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two MgO6 octahedra, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–55°. There are a spread of P–O bond distances ranging from 1.52–1.69 Å. In the sixth P site, P is bonded to four O atoms to form PO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two MgO6 octahedra, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–68°. There are a spread of P–O bond distances ranging from 1.52–1.66 Å. In the seventh P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with three MgO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–49°. There are a spread of P–O bond distances ranging from 1.52–1.63 Å. In the eighth P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with three MgO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 41–44°. There are a spread of P–O bond distances ranging from 1.52–1.65 Å. There are twenty-eight inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to one Na, one Mg, and one P atom. In the second O site, O is bonded in a 2-coordinate geometry to one Na, one Mg, and one P atom. In the third O site, O is bonded to three Na and one P atom to form a mixture of distorted edge and corner-sharing ONa3P tetrahedra. In the fourth O site, O is bonded in a 4-coordinate geometry to three Na and one P atom. In the fifth O site, O is bonded in a 3-coordinate geometry to one Na, one Mg, and one P atom. In the sixth O site, O is bonded in a 3-coordinate geometry to two equivalent Na, one Mg, and one P atom. In the seventh O site, O is bonded in a distorted trigonal planar geometry to one Na, one Mg, and one P atom. In the eighth O site, O is bonded in a distorted trigonal planar geometry to one Na, one Mg, and one P atom. In the ninth O site, O is bonded in a 3-coordinate geometry to one Na and two P atoms. In the tenth O site, O is bonded in a 2-coordinate geometry to one Na and two P atoms. In the eleventh O site, O is bonded in a distorted rectangular see-saw-like geometry to two Na, one Mg, and one P atom. In the twelfth O site, O is bonded in a 4-coordinate geometry to two Na, one Mg, and one P atom. In the thirteenth O site, O is bonded in a distorted bent 120 degrees geometry to two P atoms. In the fourteenth O site, O is bonded in a bent 120 degrees geometry to two P atoms. In the fifteenth O site, O is bonded in a distorted trigonal pyramidal geometry to two Na, one Mg, and one P atom. In the sixteenth O site, O is bonded in a 2-coordinate geometry to one Na, two Mg, and one P atom. In the seventeenth O site, O is bonded to three Na, one Mg, and one P atom to form distorted ONa3MgP trigonal bipyramids that share a cornercorner with one ONa3P tetrahedra and an edgeedge with one ONa3MgP trigonal bipyramid. In the eighteenth O site, O is bonded to three Na, one Mg, and one P atom to form distorted ONa3MgP trigonal bipyramids that share a cornercorner with one ONa3P tetrahedra, an edgeedge with one ONa3P tetrahedra, and an edgeedge with one ONa3MgP trigonal bipyramid. In the nineteenth O site, O is bonded in a 2-coordinate geometry to two equivalent Na, one Mg, and one P atom. In the twentieth O site, O is bonded in a 2-coordinate geometry to two equivalent Na, one Mg, and one P atom. In the twenty-first O site, O is bonded in a 4-coordinate geometry to one Na, two Mg, and one P atom. In the twenty-second O site, O is bonded in a 4-coordinate geometry to two Na, one Mg, and one P atom. In the twenty-third O site, O is bonded in a 4-coordinate geometry to one Na, two Mg, and one P atom. In the twenty-fourth O site, O is bonded in a 4-coordinate geometry to one Na, two Mg, and one P atom. In the twenty-fifth O site, O is bonded in a 3-coordinate geometry to two Mg and one P atom. In the twenty-sixth O site, O is bonded in a 4-coordinate geometry to two Na, one Mg, and one P atom. In the twenty-seventh O site, O is bonded in a 3-coordinate geometry to two Na, one Mg, and one P atom. In the twenty-eighth O site, O is bonded in a 3-coordinate geometry to one Na, one Mg, and one P atom.

36 MATERIALS SCIENCE↗