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49 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on V2Cu3Pb(ClO4)2 by Materials Project

V2Cu3Pb(O4Cl)2 crystallizes in the orthorhombic Ibam space group. The structure is three-dimensional. V5+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.73 Å) and two longer (1.78 Å) V–O bond length. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded in a distorted square co-planar geometry to four equivalent O2- and two equivalent Cl1- atoms. All Cu–O bond lengths are 1.97 Å. Both Cu–Cl bond lengths are 3.06 Å. In the second Cu2+ site, Cu2+ is bonded in a 4-coordinate geometry to four O2- and two equivalent Cl1- atoms. There is two shorter (1.94 Å) and two longer (1.99 Å) Cu–O bond length. There are one shorter (2.77 Å) and one longer (2.98 Å) Cu–Cl bond lengths. Pb2+ is bonded in a 8-coordinate geometry to four equivalent O2- and four equivalent Cl1- atoms. All Pb–O bond lengths are 2.66 Å. All Pb–Cl bond lengths are 3.04 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one V5+ and two Cu2+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one V5+, one Cu2+, and one Pb2+ atom. Cl1- is bonded in a 1-coordinate geometry to three Cu2+ and two equivalent Pb2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Water-Dispersible CsPbBr 3 Perovskite Nanocrystals with Ultra-Stability and its Application in Electrochemical CO 2 Reduction

Thanks to the excellent optoelectronic properties, lead halide perovskites (LHPs) have been widely employed in high-performance optoelectronic devices such as solar cells and light-emitting diodes. However, overcoming their poor stability against water has been one of the biggest challenges for most applications. Herein, we report a novel hot-injection method in a Pb-poor environment combined with a well-designed purification process to synthesize water-dispersible CsPbBr 3 nanocrystals (NCs). The as-prepared NCs sustain their superior photoluminescence (91% quantum yield in water) for more than 200 days in an aqueous environment, which is attributed to a passivation effect induced by excess CsBr salts. Thanks to the ultra-stability of these LHP NCs, for the first time, we report a new application of LHP NCs, in which they are applied to electrocatalysis of CO 2 reduction reaction. Noticeably, they show significant electrocatalytic activity (faradaic yield: 32% for CH 4 , 40% for CO) and operation stability (> 350 h).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Distribution and speciation of Sb and toxic metal(loid)s near an antimony refinery and their effects on indigenous microorganisms

Although several studies have investigated the effects of Sb contamination on surrounding environments and indigenous microorganisms, little is known about the effect of co-contamination of Sb and toxic metal(loid)s. In this study, the occurrence of Sb and other toxic metal(loid)s near an operating Sb refinery and near-field landfill site were investigated. Topsoil samples near the refinery had high Sb levels (~3250 mg kg -1 ) but relatively low concentrations of other toxic metal(loid)s. However, several soil samples taken at greater depth from the near-field landfill site contained high concentrations of As and Pb, as well as extremely high Sb contents (~21,400 mg kg -1 ). X-ray absorption fine structure analysis showed that Sb in the soils from both sites was present as Sb(V) in the form of tripuhyite (FeSbO 4 ), a stable mineral. Three-dimensional principal coordinate analysis showed that microbial community compositions in samples with high toxic metal(loid)s concentrations were significantly different from other samples and had lower microbial populations (~10 4 MPN g -1 ). Sequential extraction results revealed that Sb is present primarily in the stable residual fraction (~99 %), suggesting low Sb bioavailability. Finally, however, microbial redundancy analysis suggested that the more easily extractable Pb might be the major factor controlling microbial community compositions at the site.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗
DOE OSTI2020

Materials Data on Cu3P4Pb3O16 by Materials Project

Pb3Cu3(PO4)4 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.95 Å) and two longer (1.99 Å) Cu–O bond length. In the second Cu2+ site, Cu2+ is bonded to five O2- atoms to form CuO5 trigonal bipyramids that share corners with five PO4 tetrahedra and an edgeedge with one PbO6 octahedra. There are a spread of Cu–O bond distances ranging from 1.96–2.16 Å. There are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to six O2- atoms to form distorted PbO6 octahedra that share corners with six PO4 tetrahedra and edges with two equivalent CuO5 trigonal bipyramids. There are a spread of Pb–O bond distances ranging from 2.38–2.78 Å. In the second Pb2+ site, Pb2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Pb–O bond distances ranging from 2.45–3.25 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 a cornercorner with one PbO6 octahedra and corners with two equivalent CuO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 57°. There are a spread of P–O bond distances ranging from 1.53–1.60 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent PbO6 octahedra and corners with three equivalent CuO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 40–60°. There is three shorter (1.55 Å) and one longer (1.59 Å) P–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu2+, one Pb2+, and one P5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two Pb2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two Cu2+, one Pb2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Cu2+, one Pb2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Cu2+, two equivalent Pb2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Cu2+, one Pb2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Pb2+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one Cu2+, two Pb2+, and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe3Co(BiO3)4 by Materials Project

Fe3Co(BiO3)4 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are three inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three equivalent FeO6 octahedra and corners with three equivalent CoO6 octahedra. The corner-sharing octahedra tilt angles range from 7–17°. There are a spread of Fe–O bond distances ranging from 1.96–2.15 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form distorted corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 7–24°. There are a spread of Fe–O bond distances ranging from 1.93–2.23 Å. In the third Fe3+ site, Fe3+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share corners with three equivalent FeO6 octahedra and corners with three equivalent CoO6 octahedra. The corner-sharing octahedra tilt angles range from 19–25°. There are a spread of Fe–O bond distances ranging from 1.94–2.38 Å. Co3+ is bonded to six O2- atoms to form distorted CoO6 octahedra that share corners with six FeO6 octahedra. The corner-sharing octahedra tilt angles range from 15–25°. There are a spread of Co–O bond distances ranging from 1.87–2.42 Å. There are four inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.26–2.85 Å. In the second Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.25–2.93 Å. In the third Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.22–2.92 Å. In the fourth Bi3+ site, Bi3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Bi–O bond distances ranging from 2.22–2.60 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to one Fe3+, one Co3+, and three Bi3+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Fe3+, one Co3+, and two Bi3+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two Fe3+ and three Bi3+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Fe3+, one Co3+, and two Bi3+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one Fe3+, one Co3+, and two Bi3+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Fe3+ and two Bi3+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two Fe3+ and two Bi3+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Fe3+ and two Bi3+ atoms. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to one Fe3+, one Co3+, and two Bi3+ atoms. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to two Fe3+ and two Bi3+ atoms. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to two Fe3+ and two Bi3+ atoms. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to one Fe3+, one Co3+, and two Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe4Pb(CO)16 by Materials Project

Fe4Pb(CO)16 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four Fe4Pb(CO)16 clusters. there are four inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded in a 5-coordinate geometry to one Pb2+ and four C+1.12+ atoms. The Fe–Pb bond length is 2.67 Å. There are a spread of Fe–C bond distances ranging from 1.77–1.81 Å. In the second Fe3+ site, Fe3+ is bonded in a 5-coordinate geometry to one Pb2+ and four C+1.12+ atoms. The Fe–Pb bond length is 2.68 Å. There are a spread of Fe–C bond distances ranging from 1.78–1.81 Å. In the third Fe3+ site, Fe3+ is bonded in a 5-coordinate geometry to one Pb2+ and four C+1.12+ atoms. The Fe–Pb bond length is 2.65 Å. There are a spread of Fe–C bond distances ranging from 1.78–1.81 Å. In the fourth Fe3+ site, Fe3+ is bonded in a 5-coordinate geometry to one Pb2+ and four C+1.12+ atoms. The Fe–Pb bond length is 2.68 Å. There are a spread of Fe–C bond distances ranging from 1.77–1.81 Å. Pb2+ is bonded in a 4-coordinate geometry to four Fe3+ atoms. There are sixteen inequivalent C+1.12+ sites. In the first C+1.12+ site, C+1.12+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.12+ site, C+1.12+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.12+ site, C+1.12+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+1.12+ site, C+1.12+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fifth C+1.12+ site, C+1.12+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the sixth C+1.12+ site, C+1.12+ is bonded in a linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the seventh C+1.12+ site, C+1.12+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the eighth C+1.12+ site, C+1.12+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the ninth C+1.12+ site, C+1.12+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the tenth C+1.12+ site, C+1.12+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the eleventh C+1.12+ site, C+1.12+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the twelfth C+1.12+ site, C+1.12+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the thirteenth C+1.12+ site, C+1.12+ is bonded in a linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourteenth C+1.12+ site, C+1.12+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fifteenth C+1.12+ site, C+1.12+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the sixteenth C+1.12+ site, C+1.12+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the sixth O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the eighth O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the ninth O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the tenth O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the eleventh O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the twelfth O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the thirteenth O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the fourteenth O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the fifteenth O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom. In the sixteenth O2- site, O2- is bonded in a single-bond geometry to one C+1.12+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Operational stability of mixed Sn–Pb perovskite solar cells: Mechanisms, mitigation strategies, and perspectives

Mixed Sn–Pb perovskites provide the 1.2–1.3 eV narrow-bandgap absorber needed for high efficiency of all perovskite tandems, but their deployment is limited by operational instability under light. This review synthesizes mechanistic origins and recent mitigation strategies for mixed Sn–Pb perovskite solar cells. The oxidation of Sn 2+ to Sn 4+ , often driven by iodine formation under light and bias, is the primary failure pathway; it creates Sn vacancies, self-doping, and nonradiative loss. Surface/grain-boundary defects, halide migration, reactive oxygen species, and interfacial redox at charge-transport layers, along with hole accumulation from poor band alignment, further accelerate Sn–Pb perovskite degradation. Here we survey recent stability advances across additive chemistry, surface and grain-boundary passivation, buried-interface redesign with modified or alternative hole transport layers, and solvent systems that preserve Sn 2+ and correct Sn–Pb speciation for scalable coating. Together, these recent advances have enabled devices to retain 80%–90% output for hundreds to over a thousand hours. Lastly, we provide our perspectives on further improving the operational stability of Sn–Pb perovskite and solar cells.

14 SOLAR ENERGY↗
DOE OSTI2025

Why are Lead Iodide‐Based Perovskite Precursor Inks Yellow?

A challenge faced by metal halide perovskite (MHP) photovoltaics is scaling up solution deposition processes to realize rapid and inexpensive manufacturing. The challenge lies in completely understanding and controlling solution speciation, nucleation, and self-assembly of iodoplumbate complexes during solvent evaporation as the liquid transforms into gels and solids. An accurate description of solution species, at all points in the transformation, is a prerequisite to design robust and reliable processes. Here, in this study, the common assumption that initial monoplumbate solution species typically invoked (e.g., [PbI 6 ] 4− ) are certainly not the origin of optical absorbance at >400 nm wavelengths is disproved, as are many large particles of common “intermediate” iodoplumbate phases with face- or edge-sharing connectivity. Instead, a new perspective is offered, involving (partially) corner-sharing iodo(poly)plumbates (>1 Pb 2+ per complex) that experience highly dynamic chemical environments. It is outlined how the MHP field would benefit by elucidating these phenomena. Future work is required to determine the size and kinetic behavior of polyplumbate species, and contextualize these findings in relation to broader trends in materials chemistry beyond MHPs. Ultimately, a complete explanation for the solution speciation, optical absorbance signatures, and the color of MHP precursor inks remains an open challenge to the community.

14 SOLAR ENERGY↗
DOE OSTI2020

Materials Data on ZnP14Pb by Materials Project

ZnPbP14 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Zn2+ is bonded in a tetrahedral geometry to four P+0.29- atoms. There are a spread of Zn–P bond distances ranging from 2.44–2.50 Å. Pb2+ is bonded in a distorted square co-planar geometry to four P+0.29- atoms. There are a spread of Pb–P bond distances ranging from 2.82–3.08 Å. There are nine inequivalent P+0.29- sites. In the first P+0.29- site, P+0.29- is bonded in a trigonal non-coplanar geometry to three P+0.29- atoms. There are a spread of P–P bond distances ranging from 2.22–2.30 Å. In the second P+0.29- site, P+0.29- is bonded to one Zn2+, one Pb2+, and two equivalent P+0.29- atoms to form distorted corner-sharing PZnP2Pb tetrahedra. In the third P+0.29- site, P+0.29- is bonded to one Zn2+, one Pb2+, and two equivalent P+0.29- atoms to form distorted corner-sharing PZnP2Pb tetrahedra. Both P–P bond lengths are 2.22 Å. In the fourth P+0.29- site, P+0.29- is bonded in a trigonal non-coplanar geometry to three P+0.29- atoms. There are two shorter (2.22 Å) and one longer (2.24 Å) P–P bond lengths. In the fifth P+0.29- site, P+0.29- is bonded in a 4-coordinate geometry to one Zn2+, one Pb2+, and two P+0.29- atoms. Both P–P bond lengths are 2.20 Å. In the sixth P+0.29- site, P+0.29- is bonded in a trigonal non-coplanar geometry to three P+0.29- atoms. The P–P bond length is 2.23 Å. In the seventh P+0.29- site, P+0.29- is bonded in a trigonal non-coplanar geometry to three P+0.29- atoms. The P–P bond length is 2.23 Å. In the eighth P+0.29- site, P+0.29- is bonded in a trigonal non-coplanar geometry to three P+0.29- atoms. In the ninth P+0.29- site, P+0.29- is bonded in a trigonal non-coplanar geometry to three P+0.29- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba4TlBiPb2O9 by Materials Project

Ba4TlPb2BiO9 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to four O2- atoms. There are two shorter (2.72 Å) and two longer (2.73 Å) Ba–O bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.77–3.34 Å. In the third Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to four O2- atoms. There are a spread of Ba–O bond distances ranging from 2.70–2.81 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to four O2- atoms. There are two shorter (2.72 Å) and two longer (2.80 Å) Ba–O bond lengths. Tl1+ is bonded in a square co-planar geometry to four O2- atoms. There are two shorter (2.19 Å) and two longer (2.20 Å) Tl–O bond lengths. There are two inequivalent Pb3+ sites. In the first Pb3+ site, Pb3+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are one shorter (2.37 Å) and three longer (2.38 Å) Pb–O bond lengths. In the second Pb3+ site, Pb3+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are one shorter (2.37 Å) and three longer (2.38 Å) Pb–O bond lengths. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six O2- atoms to form corner-sharing BiO6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are a spread of Bi–O bond distances ranging from 2.04–2.21 Å. In the second Bi3+ site, Bi3+ is bonded to six O2- atoms to form corner-sharing BiO6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are a spread of Bi–O bond distances ranging from 2.04–2.21 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba2+, one Tl1+, and one Pb3+ atom. The O–Tl bond length is 2.20 Å. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, one Pb3+, and one Bi3+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to four Ba2+, one Pb3+, and one Bi3+ atom. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Ba2+, one Tl1+, and one Pb3+ atom. The O–Tl bond length is 2.19 Å. In the fifth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ba2+ and two Bi3+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to four Ba2+, one Pb3+, and one Bi3+ atom. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Ba2+, one Tl1+, and one Pb3+ atom. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba2+, one Tl1+, and one Pb3+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, one Pb3+, and one Bi3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AlCu4SbPb6S2(Cl2O13)2 by Materials Project

Cu4AlPb6SbS2(O13Cl2)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Cu3+ sites. In the first Cu3+ site, Cu3+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.84 Å) and two longer (1.95 Å) Cu–O bond length. In the second Cu3+ site, Cu3+ is bonded to six O2- atoms to form CuO6 octahedra that share a cornercorner with one SbO6 octahedra and an edgeedge with one AlO6 octahedra. The corner-sharing octahedral tilt angles are 42°. There are a spread of Cu–O bond distances ranging from 1.91–2.14 Å. Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share edges with two equivalent CuO6 octahedra. There is four shorter (1.88 Å) and two longer (2.00 Å) Al–O bond length. There are two inequivalent Pb4+ sites. In the first Pb4+ site, Pb4+ is bonded in a 8-coordinate geometry to seven O2- and one Cl1- atom. There are a spread of Pb–O bond distances ranging from 2.28–2.63 Å. The Pb–Cl bond length is 2.61 Å. In the second Pb4+ site, Pb4+ is bonded in a 6-coordinate geometry to five O2- and one Cl1- atom. There are a spread of Pb–O bond distances ranging from 2.22–2.61 Å. The Pb–Cl bond length is 2.65 Å. Sb5+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with two equivalent CuO6 octahedra. The corner-sharing octahedral tilt angles are 42°. There are two shorter (1.98 Å) and four longer (2.02 Å) Sb–O bond lengths. S6+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of S–O bond distances ranging from 1.46–1.54 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Cu3+, two equivalent Pb4+, and one Sb5+ atom. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to three Cu3+ atoms. In the third O2- site, O2- is bonded in a single-bond geometry to one Pb4+ and one S6+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Al3+ and two equivalent Pb4+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Pb4+ and one Sb5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Cu3+, one Al3+, and one Pb4+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two Cu3+ and one Pb4+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to one Pb4+ and one S6+ atom. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Pb4+ and one S6+ atom. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted single-bond geometry to one Pb4+ atom. In the second Cl1- site, Cl1- is bonded in a distorted L-shaped geometry to two equivalent Pb4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Pb-Apatite Framework as a Generator of Novel Flat-Band CuO-Based Physics

Based upon density functional theory (DFT) calculations, we present the basic electronic structure of CuPb 9 (PO 4 ) 6 O (Cu-doped lead apatite, aka LK-99), in two scenarios: (1) where the structure is constrained to the P3 symmetry and (2) where no symmetry is imposed. At the DFT level, the former is predicted to be metallic while the latter is found to be a charge-transfer insulator. In both cases the filling of these states is nominally d 9 , consistent with the standard Cu 2+ valence state, and Cu with a local magnetic moment of order 0.7 μ B . In the metallic case we find these states to be unusually flat (∼0.2 eV dispersion), giving a very high density of electronic states (DOS) at the Fermi level that we argue can be a host for novel electronic physics. The flatness of the bands is the likely origin of symmetry-lowering gapping possibilities that would remove the spectral weight from E F . Motivated by some initial experimental observations of metallic or semiconducting behavior, we propose that disorder (likely structural) is responsible for closing the gap. Here, we consider a variety of possibilities that could possibly close the charge-transfer gap but limit consideration to kinds of disorder that preserve electron count. Of the possible kinds we considered (spin disorder, O populating vacancy sites, and Cu on less energetically favorable Pb sites), the local Cu moment, and consequently the charge-transfer gap, remains robust. We conclude that disorder responsible for metallic behavior entails some kind of doping where the electron count changes. Further, we claim that the emergence of the flat bands should be due to weak wave function overlap between the orbitals on Cu and O sites, owing to the directional character of the constituent orbitals. Therefore, finding an appropriate host structure for minimizing hybridization between Cu and O while allowing them to still weakly interact should be a promising route for generating flat bands at E F which can lead to interesting electronic phenomena, regardless of whether LK-99 is a superconductor.

36 MATERIALS SCIENCE↗
DOE OSTI2024

MIBiG 4.0: advancing biosynthetic gene cluster curation through global collaboration

Specialized or secondary metabolites are small molecules of biological origin, often showing potent biological activities with applications in agriculture, engineering and medicine. Usually, the biosynthesis of these natural products is governed by sets of co-regulated and physically clustered genes known as biosynthetic gene clusters (BGCs). To share information about BGCs in a standardized and machine-readable way, the Minimum Information about a Biosynthetic Gene cluster (MIBiG) data standard and repository was initiated in 2015. Since its conception, MIBiG has been regularly updated to expand data coverage and remain up to date with innovations in natural product research. Here, we describe MIBiG version 4.0, an extensive update to the data repository and the underlying data standard. In a massive community annotation effort, 267 contributors performed 8304 edits, creating 557 new entries and modifying 590 existing entries, resulting in a new total of 3059 curated entries in MIBiG. Particular attention was paid to ensuring high data quality, with automated data validation using a newly developed custom submission portal prototype, paired with a novel peer-reviewing model. MIBiG 4.0 also takes steps towards a rolling release model and a broader involvement of the scientific community. MIBiG 4.0 is accessible online at https://mibig.secondarymetabolites.org/.

59 BASIC BIOLOGICAL SCIENCES↗