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Materials Data on Li4V2Si(PO6)2 by Materials Project

Li4V2Si(PO6)2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.07–2.74 Å. In the second Li1+ site, Li1+ is bonded to six O2- atoms to form distorted LiO6 octahedra that share a cornercorner with one SiO4 tetrahedra, corners with five PO4 tetrahedra, and faces with two VO6 octahedra. There are a spread of Li–O bond distances ranging from 2.09–2.35 Å. In the third Li1+ site, Li1+ is bonded in a 5-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.05–2.81 Å. In the fourth Li1+ site, Li1+ is bonded to six O2- atoms to form distorted LiO6 octahedra that share a cornercorner with one SiO4 tetrahedra, corners with five PO4 tetrahedra, and faces with two VO6 octahedra. There are a spread of Li–O bond distances ranging from 2.09–2.36 Å. In the fifth Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.06–2.76 Å. In the sixth Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.09–2.71 Å. In the seventh Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.06–2.79 Å. In the eighth Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.09–2.72 Å. In the ninth Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.05–2.78 Å. In the tenth Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.06–2.74 Å. In the eleventh Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.07–2.75 Å. In the twelfth Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.04–2.78 Å. In the thirteenth Li1+ site, Li1+ is bonded to six O2- atoms to form distorted LiO6 octahedra that share corners with three SiO4 tetrahedra, corners with three PO4 tetrahedra, and faces with two VO6 octahedra. There are a spread of Li–O bond distances ranging from 2.10–2.33 Å. In the fourteenth Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.06–2.75 Å. In the fifteenth Li1+ site, Li1+ is bonded to six O2- atoms to form distorted LiO6 octahedra that share corners with three SiO4 tetrahedra, corners with three PO4 tetrahedra, and faces with two VO6 octahedra. There are a spread of Li–O bond distances ranging from 2.10–2.33 Å. In the sixteenth Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.07–2.75 Å. There are eight inequivalent V3+ sites. In the first V3+ site, V3+ is bonded to six O2- atoms to form VO6 octahedra that share a cornercorner with one SiO4 tetrahedra, corners with five PO4 tetrahedra, and a faceface with one LiO6 octahedra. There are a spread of V–O bond distances ranging from 1.92–2.09 Å. In the second V3+ site, V3+ is bonded to six O2- atoms to form VO6 octahedra that share corners with three SiO4 tetrahedra, corners with three PO4 tetrahedra, and a faceface with one LiO6 octahedra. There are a spread of V–O bond distances ranging from 1.94–2.10 Å. In the third V3+ site, V3+ is bonded to six O2- atoms to form VO6 octahedra that share a cornercorner with one SiO4 tetrahedra, corners with five PO4 tetrahedra, and a faceface with one LiO6 octahedra. There are a spread of V–O bond distances ranging from 1.92–2.09 Å. In the fourth V3+ site, V3+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two SiO4 tetrahedra, corners with four PO4 tetrahedra, and a faceface with one LiO6 octahedra. There are a spread of V–O bond distances ranging from 1.94–2.09 Å. In the fifth V3+ site, V3+ is bonded to six O2- atoms to form VO6 octahedra that share corners with three SiO4 tetrahedra, corners with three PO4 tetrahedra, and a faceface with one LiO6 octahedra. There are a spread of V–O bond distances ranging from 1.94–2.11 Å. In the sixth V3+ site, V3+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two SiO4 tetrahedra, corners with four PO4 tetrahedra, and a faceface with one LiO6 octahedra. There are a spread of V–O bond distances ranging from 1.94–2.08 Å. In the seventh V3+ site, V3+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two SiO4 tetrahedra, corners with four PO4 tetrahedra, and a faceface with one LiO6 octahedra. There are a spread of V–O bond distances ranging from 1.94–2.10 Å. In the eighth V3+ site, V3+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two SiO4 tetrahedra, corners with four PO4 tetrahedra, and a faceface with one LiO6 octahedra. There are a spread of V–O bond distances ranging from 1.94–2.10 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two LiO6 octahedra and corners with four VO6 octahedra. The corner-sharing octahedra tilt angles range from 31–45°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two LiO6 octahedra and corners with four VO6 octahedra. The corner-sharing octahedra tilt angles range from 30–44°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two LiO6 octahedra and corners with four VO6 octahedra. The corner-sharing octahedra tilt angles range from 30–44°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two LiO6 octahedra and corners with four VO6 octahedra. The corner-sharing octahedra tilt angles range from 31–45°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. There are eight inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and corners with four VO6 octahedra. The corner-sharing octahedra tilt angles range from 30–45°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and corners with four VO6 octahedra. The corner-sharing octahedra tilt angles range from 30–47°. There are a spread of P–O bond distances ranging from 1.53–1.56 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and corners with four VO6 octahedra. The corner-sharing octahedra tilt angles range from 30–45°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and corners with four VO6 octahedra. The corner-sharing octahedra tilt angles range from 30–46°. There are a spread of P–O bond distances ranging from 1.53–1.57 Å. In the fifth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and corners with four VO6 octahedra. The corner-sharing octahedra tilt angles range from 30–47°. There is two shorter (1.53 Å) and two longer (1.57 Å) P–O bond length. In the sixth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and corners with four VO6 octahedra. The corner-sharing octahedra tilt angles range from 30–46°. There are a spread of P–O bond distances ranging from 1.53–1.56 Å. In the seventh P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and corners with four VO6 octahedra. The corner-sharing octahedra tilt angles range from 29–43°. There are a spread of P–O bond distances ranging from 1.53–1.57 Å. In the eighth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and corners with four VO6 octahedra. The corner-sharing octahedra tilt angles range from 29–43°. There are a spread of P–O bond distances ranging from 1.53–1.57 Å. There are forty-eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+, one V3+, and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V3+, and one P5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+, one V3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+, one V3+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V3+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V3+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+, one V3+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V3+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V3+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 5-coordinate geometry to three Li1+, one V3+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+, one V3+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+, one V3+, and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a 5-coordinate geometry to three Li1+, one V3+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V3+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V3+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+, one V3+, and one P5+ atom. In the seventeenth O2- site, O2- is bonded to three Li1+, one V3+, and one Si4+ atom to form distorted corner-sharing OLi3VSi trigonal bipyramids. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V3+, and one P5+ atom. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V3+, and one Si4+ atom. In the twentieth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V3+, and one P5+ atom. In the twenty-first O2- site, O2- is bonded in a 5-coordinate geometry to three Li1+, one V3+, and one Si4+ atom. In the twenty-second O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V3+, and one P5+ atom. In the twenty-third O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V3+, and one Si4+ atom. In the twenty-fourth O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+, one V3+, and one P5+ atom. In the twenty-fifth O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+, one V3+, and one P5+ atom. In the twenty-sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V3+, and one P5+ atom. In the twenty-seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+, one V3+, and one P5+ atom. In the twenty-eighth O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+, one V3+, and one P5+ atom. In the twenty-ninth O2- site, O2- is bonded in a 3-coordinate geometry

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K4Na4VMo7O20 by Materials Project

K4Na4VMo7O20 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of K–O bond distances ranging from 1.67–2.52 Å. In the second K1+ site, K1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of K–O bond distances ranging from 1.67–2.48 Å. In the third K1+ site, K1+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of K–O bond distances ranging from 1.69–2.52 Å. In the fourth K1+ site, K1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of K–O bond distances ranging from 1.65–2.50 Å. In the fifth K1+ site, K1+ is bonded in a 1-coordinate geometry to four O2- atoms. There are a spread of K–O bond distances ranging from 1.57–3.17 Å. In the sixth K1+ site, K1+ is bonded in a 1-coordinate geometry to four O2- atoms. There are a spread of K–O bond distances ranging from 1.66–3.02 Å. In the seventh K1+ site, K1+ is bonded in a 2-coordinate geometry to four O2- atoms. There are a spread of K–O bond distances ranging from 1.62–3.07 Å. In the eighth K1+ site, K1+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of K–O bond distances ranging from 1.65–2.76 Å. In the ninth K1+ site, K1+ is bonded in a 1-coordinate geometry to four O2- atoms. There are a spread of K–O bond distances ranging from 1.60–3.13 Å. In the tenth K1+ site, K1+ is bonded in a 1-coordinate geometry to three O2- atoms. There are one shorter (1.95 Å) and two longer (2.50 Å) K–O bond lengths. In the eleventh K1+ site, K1+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of K–O bond distances ranging from 1.91–2.55 Å. In the twelfth K1+ site, K1+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of K–O bond distances ranging from 2.01–2.52 Å. In the thirteenth K1+ site, K1+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of K–O bond distances ranging from 1.85–2.55 Å. In the fourteenth K1+ site, K1+ is bonded in a 1-coordinate geometry to four O2- atoms. There are a spread of K–O bond distances ranging from 2.01–3.25 Å. In the fifteenth K1+ site, K1+ is bonded in a 1-coordinate geometry to two O2- atoms. There are one shorter (1.93 Å) and one longer (2.37 Å) K–O bond lengths. In the sixteenth K1+ site, K1+ is bonded in a distorted single-bond geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 1.86–3.22 Å. There are sixteen inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 1.56–2.25 Å. In the second Na1+ site, Na1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 1.55–2.34 Å. In the third Na1+ site, Na1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 1.55–2.31 Å. In the fourth Na1+ site, Na1+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 1.54–2.48 Å. In the fifth Na1+ site, Na1+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 1.47–2.69 Å. In the sixth Na1+ site, Na1+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 1.54–2.53 Å. In the seventh Na1+ site, Na1+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 1.49–2.67 Å. In the eighth Na1+ site, Na1+ is bonded in a 2-coordinate geometry to two O2- atoms. There is one shorter (1.83 Å) and one longer (2.16 Å) Na–O bond length. In the ninth Na1+ site, Na1+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 1.81–2.92 Å. In the tenth Na1+ site, Na1+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 1.73–2.89 Å. In the eleventh Na1+ site, Na1+ is bonded in a distorted single-bond geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 1.65–2.88 Å. In the twelfth Na1+ site, Na1+ is bonded in a 1-coordinate geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 1.79–2.99 Å. In the thirteenth Na1+ site, Na1+ is bonded in a distorted single-bond geometry to two O2- atoms. There are one shorter (1.69 Å) and one longer (2.61 Å) Na–O bond lengths. In the fourteenth Na1+ site, Na1+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 1.79–2.84 Å. In the fifteenth Na1+ site, Na1+ is bonded in a distorted single-bond geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 1.71–3.03 Å. In the sixteenth Na1+ site, Na1+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 1.83–2.88 Å. There are four inequivalent V2+ sites. In the first V2+ site, V2+ is bonded in a 2-coordinate geometry to five O2- atoms. There are a spread of V–O bond distances ranging from 1.90–2.81 Å. In the second V2+ site, V2+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of V–O bond distances ranging from 1.73–2.62 Å. In the third V2+ site, V2+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of V–O bond distances ranging from 1.77–1.93 Å. In the fourth V2+ site, V2+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of V–O bond distances ranging from 1.68–2.02 Å. There are twenty-eight inequivalent Mo+4.29+ sites. In the first Mo+4.29+ site, Mo+4.29+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 2.08–2.30 Å. In the second Mo+4.29+ site, Mo+4.29+ is bonded in a 4-coordinate geometry to four O2- atoms. There are two shorter (2.12 Å) and two longer (2.31 Å) Mo–O bond lengths. In the third Mo+4.29+ site, Mo+4.29+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 2.07–2.25 Å. In the fourth Mo+4.29+ site, Mo+4.29+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 2.08–2.30 Å. In the fifth Mo+4.29+ site, Mo+4.29+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 2.09–2.22 Å. In the sixth Mo+4.29+ site, Mo+4.29+ is bonded in a 8-coordinate geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 2.10–2.40 Å. In the seventh Mo+4.29+ site, Mo+4.29+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 2.06–2.24 Å. In the eighth Mo+4.29+ site, Mo+4.29+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 2.07–2.34 Å. In the ninth Mo+4.29+ site, Mo+4.29+ is bonded in a square co-planar geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 1.86–2.07 Å. In the tenth Mo+4.29+ site, Mo+4.29+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 1.81–2.08 Å. In the eleventh Mo+4.29+ site, Mo+4.29+ is bonded in a square co-planar geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 1.85–2.07 Å. In the twelfth Mo+4.29+ site, Mo+4.29+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 1.86–2.13 Å. In the thirteenth Mo+4.29+ site, Mo+4.29+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 1.85–2.08 Å. In the fourteenth Mo+4.29+ site, Mo+4.29+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 1.78–2.08 Å. In the fifteenth Mo+4.29+ site, Mo+4.29+ is bonded in a square co-planar geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 1.92–2.06 Å. In the sixteenth Mo+4.29+ site, Mo+4.29+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 1.79–2.09 Å. In the seventeenth Mo+4.29+ site, Mo+4.29+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of Mo–O bond distances ranging from 1.85–2.44 Å. In the eighteenth Mo+4.29+ site, Mo+4.29+ is bonded in a distorted water-like geometry to three O2- atoms. There are a spread of Mo–O bond distances ranging from 1.81–2.61 Å. In the nineteenth Mo+4.29+ site, Mo+4.29+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of Mo–O bond distances ranging from 1.85–2.57 Å. In the twentieth Mo+4.29+ site, Mo+4.29+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of Mo–O bond distances ranging from 1.82–2.49 Å. In the twenty-first Mo+4.29+ site, Mo+4.29+ is bonded in a distorted water-like geometry to three O2- atoms. There are a spread of Mo–O bond distances ranging from 1.97–2.69 Å. In the twenty-second Mo+4.29+ site, Mo+4.29+ is bonded in a distorted water-like geometry to three O2- atoms. There are a spread of Mo–O bond distances ranging from 1.90–2.68 Å. In the twenty-third Mo+4.29+ site, Mo+4.29+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of Mo–O bond distances ranging from 1.79–2.24 Å. In the twenty-fourth Mo+4.29+ site, Mo+4.29+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Mo–O bond distances ranging from 1.93–2.05 Å. In the twenty-fifth Mo+4.29+ site, Mo+4.29+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Mo–O bond distances ranging from 1.94–2.16 Å. In the twenty-sixth Mo+4.29+ site, Mo+4.29+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of Mo–O bond distances ranging from 1.72–2.11 Å. In the twenty-seventh Mo+4.29+ site, Mo+4.29+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Mo–O bond distances ranging from 1.96–2.13 Å. In the twenty-eighth Mo+4.29+ site, Mo+4.29+ is bonded in a 1-coordinate geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 1.63–2.43 Å. There are eighty inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, one Na1+, and two Mo+4.29+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two K1+ and two Mo+4.29+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+ and two Mo+4.29+ atoms. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one K1+, one Na1+, and two Mo+4.29+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, one Na1+, and two Mo+4.29+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, one Na1+, and two Mo+4.29+ atoms. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one K1+, one Na1+, and two Mo+4.29+ atoms. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two K1+ and two Mo+4.29+ atoms. In the ninth O2- site, O2- is bonded in a distorted linear geometry to two Mo+4.29+ atoms. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to two Mo+4.29+ and one O2- atom. The O–O bond length is 1.93 Å. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to two Mo+4.29+ atoms. In the twelfth O2- site, O2- is bonded in a 1-coordinate geome

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2Na4Li2Ti4Mn3Fe(SiO3)16 by Materials Project

K2Na4Li2Ti4Mn3Fe(SiO3)16 is Esseneite-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.80–3.23 Å. In the second K1+ site, K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.81–3.24 Å. 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 2.36–3.01 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 2.36–3.02 Å. In the third 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 2.36–3.02 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 2.36–3.03 Å. There are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with four SiO4 tetrahedra, an edgeedge with one MnO6 octahedra, an edgeedge with one FeO6 octahedra, and edges with four TiO6 octahedra. There are a spread of Li–O bond distances ranging from 2.05–2.28 Å. In the second Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with four SiO4 tetrahedra, edges with two MnO6 octahedra, and edges with four TiO6 octahedra. There are a spread of Li–O bond distances ranging from 2.06–2.27 Å. There are four inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share a cornercorner with one FeO6 octahedra, corners with five SiO4 tetrahedra, an edgeedge with one TiO6 octahedra, an edgeedge with one MnO6 octahedra, and edges with two LiO6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are a spread of Ti–O bond distances ranging from 1.73–2.27 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share a cornercorner with one MnO6 octahedra, corners with five SiO4 tetrahedra, an edgeedge with one TiO6 octahedra, an edgeedge with one MnO6 octahedra, and edges with two LiO6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are a spread of Ti–O bond distances ranging from 1.73–2.25 Å. In the third Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share a cornercorner with one MnO6 octahedra, corners with five SiO4 tetrahedra, an edgeedge with one TiO6 octahedra, an edgeedge with one MnO6 octahedra, and edges with two LiO6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are a spread of Ti–O bond distances ranging from 1.73–2.26 Å. In the fourth Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share a cornercorner with one MnO6 octahedra, corners with five SiO4 tetrahedra, an edgeedge with one TiO6 octahedra, an edgeedge with one FeO6 octahedra, and edges with two LiO6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are a spread of Ti–O bond distances ranging from 1.73–2.24 Å. There are three inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share a cornercorner with one TiO6 octahedra, corners with five SiO4 tetrahedra, an edgeedge with one LiO6 octahedra, an edgeedge with one TiO6 octahedra, and an edgeedge with one MnO6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are a spread of Mn–O bond distances ranging from 2.08–2.33 Å. In the second Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share a cornercorner with one TiO6 octahedra, corners with five SiO4 tetrahedra, an edgeedge with one LiO6 octahedra, an edgeedge with one TiO6 octahedra, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are a spread of Mn–O bond distances ranging from 2.08–2.32 Å. In the third Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share a cornercorner with one TiO6 octahedra, corners with five SiO4 tetrahedra, an edgeedge with one LiO6 octahedra, an edgeedge with one TiO6 octahedra, and an edgeedge with one MnO6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are a spread of Mn–O bond distances ranging from 2.08–2.33 Å. Fe2+ is bonded to six O2- atoms to form FeO6 octahedra that share a cornercorner with one TiO6 octahedra, corners with five SiO4 tetrahedra, an edgeedge with one LiO6 octahedra, an edgeedge with one TiO6 octahedra, and an edgeedge with one MnO6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are a spread of Fe–O bond distances ranging from 2.02–2.31 Å. There are sixteen inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one TiO6 octahedra, a cornercorner with one MnO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–61°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one TiO6 octahedra, a cornercorner with one MnO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–61°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one TiO6 octahedra, a cornercorner with one FeO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–59°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one TiO6 octahedra, a cornercorner with one MnO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–61°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one MnO6 octahedra, a cornercorner with one FeO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two MnO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–63°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the seventh Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one MnO6 octahedra, a cornercorner with one FeO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–63°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the eighth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two MnO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–63°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the ninth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one LiO6 octahedra, corners with three TiO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–62°. There are a spread of Si–O bond distances ranging from 1.63–1.68 Å. In the tenth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one LiO6 octahedra, corners with three TiO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–61°. There are a spread of Si–O bond distances ranging from 1.63–1.68 Å. In the eleventh Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one LiO6 octahedra, corners with three TiO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–62°. There are a spread of Si–O bond distances ranging from 1.63–1.68 Å. In the twelfth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one LiO6 octahedra, corners with three TiO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–62°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. In the thirteenth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one LiO6 octahedra, a cornercorner with one TiO6 octahedra, a cornercorner with one MnO6 octahedra, a cornercorner with one FeO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–65°. There are a spread of Si–O bond distances ranging from 1.61–1.70 Å. In the fourteenth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one LiO6 octahedra, a cornercorner with one TiO6 octahedra, a cornercorner with one MnO6 octahedra, a cornercorner with one FeO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–65°. There are a spread of Si–O bond distances ranging from 1.60–1.70 Å. In the fifteenth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one LiO6 octahedra, a cornercorner with one TiO6 octahedra, corners with two MnO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–65°. There are a spread of Si–O bond distances ranging from 1.60–1.70 Å. In the sixteenth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one LiO6 octahedra, a cornercorner with one TiO6 octahedra, corners with two MnO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–64°. There are a spread of Si–O bond distances ranging from 1.60–1.70 Å. There are forty-eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ti4+, one Fe2+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ti4+, one Mn2+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ti4+, one Mn2+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ti4+, one Mn2+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Fe2+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mn2+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mn2+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a 3-coordinate geome

36 MATERIALS SCIENCE↗
DOE OSTI2021

Structural analysis of the PTEN:P-Rex2 signaling complex reveals how cancer-associated mutations coordinate to hyperactivate Rac1

The dual-specificity phosphatase PTEN functions as a tumor suppressor by hydrolyzing PI(3,4,5)P 3 to PI(4,5)P 2 to inhibit PI3K-AKT signaling and cellular proliferation. P-Rex2 is a guanine nucleotide exchange factor for Rho GTPases and can be activated by Gβγ subunits downstream of G protein–coupled receptor signaling and by PI(3,4,5)P 3 downstream of receptor tyrosine kinases. The PTEN:P-Rex2 complex is a commonly mutated signaling node in metastatic cancer. Assembly of the PTEN:P-Rex2 complex inhibits the activity of both proteins, and its dysregulation can drive PI3K-AKT signaling and cellular proliferation. Here, using cross-linking mass spectrometry and functional studies, we gained mechanistic insights into PTEN:P-Rex2 complex assembly and coinhibition. We found that PTEN was anchored to P-Rex2 by interactions between the PDZ-interacting motif in the PTEN C-terminal tail and the second PDZ domain of P-Rex2. This interaction bridged PTEN across the P-Rex2 surface, preventing PI(3,4,5)P 3 hydrolysis. Conversely, PTEN both allosterically promoted an autoinhibited conformation of P-Rex2 and blocked its binding to Gβγ. In addition, we observed that the PTEN-deactivating mutations and P-Rex2 truncations combined to drive Rac1 activation to a greater extent than did either single variant alone. These insights enabled us to propose a class of gain-of-function, cancer-associated mutations within the PTEN:P-Rex2 interface that uncouple PTEN from the inhibition of Rac1 signaling.

D’Andrea, Laura↗
DOE OSTI2025

Mixed-valence halide perovskites

Mixed-valence compounds—which feature an element in at least two different oxidation states—can display emergent optical and transport phenomena stemming from electron transfer between the different valences (intervalence charge-transfer; IVCT). As halide perovskites show promise as active materials in numerous optoelectronic devices, it is an opportune moment to incorporate and study the effects of mixed-valence in this versatile materials family, to access tunable electronic structures ranging from insulators to semiconductors to metals. Herein, we introduce the basic concepts of mixed-valence in molecules and discuss how these concepts may be extended to mixed-valence in extended solids. We then review the few studies of mixed valence in 3D and 2D halide perovskites and halide perovskites with mixed-valence impurities, ranging from studies in the early 1900s to the present day. In conclusion, through judicious choice of metal ion, its coordinating ligands and their geometry, and overall structural dimensionality, chemists can exert powerful synthetic control over electronic delocalization in mixed-valence perovskites, and we hope to see this intriguing materials class expand to encompass new compositions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Artificial Iron Proteins: Modeling the Active Sites in Non-Heme Dioxygenases

An important class of non-heme dioxygenases contains a conserved Fe binding site that consists of a 2-His-1-carboxylate facial triad. Results from structural biology show that, in the resting state, these proteins are six-coordinate with aqua ligands occupying the remaining three coordination sites. Here, we have utilized biotin–streptavidin (Sav) technology to design new artificial Fe proteins (ArMs) that have many of the same structural features found within active sites of these non-heme dioxygenases. An Sav variant was isolated that contains the S 112 E mutation, which installed a carboxylate side chain in the appropriate position to bind to a synthetic Fe II complex confined within Sav. Structural studies using X-ray diffraction (XRD) methods revealed a facial triad binding site that is composed of two N donors from the biotinylated ligand and the monodentate coordination of the carboxylate from S 112 E. Two aqua ligands complete the primary coordination sphere of the Fe II center with both involved in hydrogen bond networks within Sav. The corresponding Fe III protein was also prepared and structurally characterized to show a six-coordinate complex with two exogenous acetato ligands. The Fe III protein was further shown to bind an exogenous azido ligand through replacement of one acetato ligand. Spectroscopic studies of the ArMs in solution support the results found by XRD.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Reining in Radium for Nuclear Medicine: Extra-Large Chelator Development for an Extra-Large Ion

Targeted α therapy (TAT) of soft-tissue cancers using the α particle-emitting radionuclide 223 Ra holds great potential because of its favorable nuclear properties, adequate availability, and established clinical use for treating metastatic prostate cancer of the bone. Despite these advantages, the use of 223 Ra has been largely overshadowed by other α emitters due to its challenging chelation chemistry. A key criterion that needs to be met for a radionuclide to be used in TAT is its stable attachment to a targeting vector via a bifunctional chelator. The low charge density of Ra 2+ arising from its large ionic radius weakens its electrostatic binding interactions with chelators, leading to insufficient complex stability in vivo. In this study, we synthesized and evaluated macropa-XL as a novel chelator for 223 Ra. It bears a large 21-crown-7 macrocyclic core and two picolinate pendent groups, which we hypothesized would effectively saturate the large coordination sphere of the Ra 2+ ion. The structural chemistry of macropa-XL was first established with the nonradioactive Ba 2+ ion using X-ray diffraction and X-ray absorption spectroscopy, which revealed the formation of an 11-coordinate complex in a rare anti pendent-arm configuration. Subsequently, the stability constant of the [Ra(macropa-XL)] complex was determined via competitive cation exchange with 223 Ra and 224 Ra radiotracers and compared with that of macropa, the current state-of-the-art chelator for Ra 2+ . A moderate log K ML value of 8.12 was measured for [Ra(macropa-XL)], which is approximately 1.5 log K units lower than the stability constant of [Ra(macropa)]. This relative decrease in Ra 2+ complex stability for macropa-XL versus macropa was further probed using density functional theory calculations. Additionally, macropa-XL was radiolabeled with 223 Ra, and the kinetic stability of the resulting complex was evaluated in human serum. Furthermore, although macropa-XL could effectively bind 223 Ra under mild conditions, the complex appeared to be unstable to transchelation. Collectively, this study sheds additional light on the chelation chemistry of the exotic Ra 2+ ion and contributes to the small, but growing, number of chelator development efforts for 223 Ra-based TAT.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Nanotubes from the Misfit Layered Compound (SmS) 1.19 TaS 2 : Atomic Structure, Charge Transfer, and Electrical Properties

Misfit layered compounds (MLCs) MX-TX 2 , where M, T = metal atoms and X = S, Se, or Te, and their nanotubes are of significant interest due to their rich chemistry and unique quasi-1D structure. In particular, LnX-TX 2 (Ln = rare-earth atom) constitute a relatively large family of MLCs, from which nanotubes have been synthesized. The properties of MLCs can be tuned by the chemical and structural interplay between LnX and TX 2 sublayers and alloying of each of the Ln, T, and X elements. In order to engineer them to gain desirable performance, a detailed understanding of their complex structure is indispensable. MLC nanotubes are a relative newcomer and offer new opportunities. In particular, like WS 2 nanotubes before, the confinement of the free carriers in these quasi-1D nanostructures and their chiral nature offer intriguing physical behavior. High-resolution transmission electron microscopy in conjunction with a focused ion beam are engaged to study SmS-TaS 2 nanotubes and their cross-sections at the atomic scale. The atomic resolution images distinctly reveal that Ta is in trigonal prismatic coordination with S atoms in a hexagonal structure. Furthermore, the position of the sulfur atoms in both the SmS and the TaS 2 sublattices is revealed. X-ray photoelectron spectroscopy, electron energy loss spectroscopy, and X-ray absorption spectroscopy are carried out. These analyses conclude that charge transfer from the Sm to the Ta atoms leads to filling of the Ta 5d z 2 level, which is confirmed by density functional theory (DFT) calculations. Transport measurements show that the nanotubes are semimetallic with resistivities in the range of 10 –4 Ω·cm at room temperature, and magnetic susceptibility measurements show a superconducting transition at 4 K.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Electrochemical Oxidation in Garnet-Type Solid Electrolyte by Formation of Point Defects

All-solid-state batteries hold greater promise for improving safety and energy density over conventional battery technology employing organic liquid electrolytes. One of the required features of a Li + conducting solid electrolyte is electrochemical stability, attained thermodynamically or kinetically, within the targeted operating voltage and temperature ranges. Therefore, understanding of the oxidative or reductive degradation mechanism is important to allow the design of stable solid electrolyte materials. This work contributes to building an understanding of the oxidative degradation mechanism in lithium solid electrolytes at cell operating conditions. Here, we have focused on resolving the oxidative decomposition mechanism of Al-doped lithium garnet Li 6.28 Al 0.24 La 3 Zr 2 O 12 (LLZO) as a state-of-the-art inorganic ceramic electrolyte. By combining experimental and computational analyses, we show that oxidation of LLZO occurs by simultaneous loss of oxygen and lithium from the structure, resulting in substoichiometric LLZO, at a moderate temperature (80 °C) and a high electrode potential (4.3 V vs Li/Li + ). Based on X-ray absorption and diffraction analyses, we find that the zirconium coordination shells in LLZO contract while the crystal structure experiences positive chemical strain upon electrochemical oxidation. The results from ex situ structural characterization of both the local structure and crystal symmetry are supported by a substoichiometric LLZO with lithium and oxygen vacancies, modeled by density functional theory (DFT) calculations. These chemical and structural changes in LLZO suppress effective lithium-ion conductivity by an order of magnitude. Formation of lithium and oxygen vacancies in LLZO upon electrochemical oxidation is different from prior thermodynamic predictions of phase decomposition of LLZO. The difference here is that the experiments were conducted at near-room temperature, which can hinder the kinetics of phase separation, and thus, the resultant LLZO solid electrolyte is still single-phase but substoichiometric in Li and O. In conclusion, these findings contribute an important degradation mechanism of the electrolyte, relevant for practical operational conditions of solid-state batteries.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Template-free fabrication of fractal porous Y 2 O 3 monolithic foam and its functional modification by Ni-doping

Fractal structures which display nearly the same character at every scale exist widely in nature, however, it is still a great challenge to fabricate a fractal nanostructure. Herein, a Y 2 O 3 monolith with unique hierarchically fractal porous structure was fabricated via calcination of a fractal porous coordination polymer precursor. The monolith exhibits porous feature with the pore-size ranging from micrometers to nanometers. Interestingly, each level of the pore-wall is composed of secondary porous structures, whose pore-wall is composed of sub-level self-similar porous feature. Moreover, by Ni-doping in the coordination polymer precursor, fractal porous Ni@Y 2 O 3 was prepared, and exhibited enhanced activity in ethanol steam reforming compared with that of a common supported NiO catalyst.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Intra- and Intermolecular Self-Assembly of a 20-nm-Wide Supramolecular Hexagonal Grid.

For the past three decades, the coordination-driven self-assembly of three-dimensional structures has undergone rapid progress; however, parallel efforts to create large discrete two-dimensional architectures-as opposed to polymers-have met with limited success. The synthesis of metallo-supramolecular systems with well-defined shapes and sizes in the range of 10-100 nm remains challenging. Here we report the construction of a series of giant supramolecular hexagonal grids, with diameters on the order of 20 nm and molecular weights greater than 65 kDa, through a combination of intra- and intermolecular metal-mediated self-assembly steps. The hexagonal intermediates and the resulting self-assembled grid architectures were imaged at submolecular resolution by scanning tunnelling microscopy. Characterization (including by scanning tunnelling spectroscopy) enabled the unambiguous atomic-scale determination of fourteen hexagonal grid isomers.

Zhang, Zhe↗
NASA NTRS1983

Nonlinear structural dynamics analysis using a modified modal method

The procedure for predicting the nonlinear dynamic response of structural components subjected to a step loading is presented. The procedure is a modified modal method that involves a change of dependent variables from the unknown nodal degrees of freedom of the finite element model of the structure to a smaller set of generalized coordinates. This change of dependent variables uses a combination of the nonlinear static solution and some selected vibration mode shapes. The vibration mode shapes correspond to the eigenvectors obtained by solving a standard free vibration eigenvalue problem wherein the stiffness matrix is expanded about the nonlinear static solution. A strategy is also presented for determining which and how many vibration mode shapes to include in the transformation. The effect of inaccurate representation of the spatial distribution of the applied load on the nonlinear dynamic response is discussed for two classes of structural behavior. Application of the procedure to structures which exhibit a stiffening behavior and to those with a softening behavior is presented.

Knight, N. F., Jr.↗
NASA NTRS1989

Model reduction for flexible spacecraft with clustered natural frequencies

Two approaches to the problem of model reduction for flexible spacecraft that have proved very useful are balancing and model truncation. Furthermore, it is well known that a model representation of a lightly damped flexible structure with widely spaced natural frequencies is approximately balanced. Consequently, reduction in either coordinate system gives similar results for this case. It is important to note, however, that flexible space structures typically have clusters of closely spaced frequencies. In such cases, reduction in model coordinates can give large errors, while the error obtained using balancing is generally much smaller. A new reduction procedure which combines the best features of model and balanced reduction is therefore developed. It is more efficient than balanced reduction of the full system, as it only involves balancing those subsystems of close modes that are highly correlated, yet is shown to yield results which are essentially as good.

Williams, T. W. C.↗
NASA NTRS1992

Pressure-induced coordination changes in alkali-germanate melts - An in situ spectroscopic investigation

The structure of liquid Na2Ge2O5-H2O, a silicate melt analog, has been studied with Raman spectroscopy to pressures of 2.2 gigapascals. Upon compression, a peak near more than 240 wavenumbers associated with octahedral GeO6 groups grows relative to a peak near 500 wavenumbers associated with tetrahedral GeO4 groups. This change corresponds to an increase in octahedral germanium in the liquid from near 0 percent at ambient pressures to more than 50 percent at a pressure of 2.2 gigapascals. Silicate liquids pausibly undergo similar coordination changes at depth in the earth. Such structural changes may generate decreases in the fusion slopes of silicates at high pressures as well as neutrally buoyant magmas within the transition zone of the earth's mantle.

Farber, Danial L.↗
DOE OSTI2023

Jahn–Teller-driven phase segregation in Mn x Co 3–x O 4 spinel thin films

Transition metal spinel oxides comprised of earth-abundant Mn and Co have long been explored for their use in catalytic reactions and energy storage. However, understanding functional properties can be challenging due to differences in sample preparation and the ultimate structural properties of the materials. Epitaxial thin film synthesis provides a novel means of producing precisely controlled materials to explore the variations reported in the literature. In this work, Mn x Co 3–x O 4 samples from x = 0 to x = 1.28 were synthesized through molecular beam epitaxy and characterized to develop a material properties map as a function of stoichiometry. Here, films were characterized via in situ x-ray photoelectron spectroscopy, x-ray diffraction, scanning transmission electron microscopy, and polarized K-edge x-ray absorption spectroscopy. Mn cations within this range were found to be octahedrally coordinated, in line with an inverse spinel structure. Samples largely show mixed Mn 3+ and Mn 4+ character with evidence of phase segregation tendencies with the increasing Mn content and increasing Mn 3+ formal charge. Phase segregation may occur due to structural incompatibility between cubic and tetragonal crystal structures associated with Mn 4+ and Jahn–Teller active Mn 3+ octahedra, respectively. Our results help in explaining the reported differences across samples in these promising materials for renewable energy technologies.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2020

Materials Data on MgPt by Materials Project

MgPt is alpha-derived structured and crystallizes in the cubic P2_13 space group. The structure is three-dimensional. Mg2+ is bonded in a 7-coordinate geometry to seven equivalent Pt2- atoms. There are a spread of Mg–Pt bond distances ranging from 2.67–2.78 Å. Pt2- is bonded in a 7-coordinate geometry to seven equivalent Mg2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SnPd by Materials Project

PdSn is Modderite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Pd is bonded in a 6-coordinate geometry to six equivalent Sn atoms. There are a spread of Pd–Sn bond distances ranging from 2.70–2.85 Å. Sn is bonded in a 6-coordinate geometry to six equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ge2Os by Materials Project

OsGe2 is Magnesium tetraboride-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Os is bonded in a 8-coordinate geometry to eight Ge atoms. There are a spread of Os–Ge bond distances ranging from 2.53–2.73 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 4-coordinate geometry to three equivalent Os and three equivalent Ge atoms. There are one shorter (2.41 Å) and two longer (2.72 Å) Ge–Ge bond lengths. In the second Ge site, Ge is bonded in a 5-coordinate geometry to five equivalent Os atoms.

36 MATERIALS SCIENCE↗