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At least 685 records · Page 38
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on GaCuTe2 by Materials Project

CuGaTe2 is Caswellsilverite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to six Te2- atoms to form CuTe6 octahedra that share corners with two equivalent GaTe6 octahedra, corners with four equivalent CuTe6 octahedra, edges with four equivalent CuTe6 octahedra, and edges with eight GaTe6 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. There are a spread of Cu–Te bond distances ranging from 2.77–2.89 Å. In the second Cu1+ site, Cu1+ is bonded to six Te2- atoms to form CuTe6 octahedra that share corners with two equivalent GaTe6 octahedra, corners with four equivalent CuTe6 octahedra, edges with four equivalent CuTe6 octahedra, and edges with eight GaTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Cu–Te bond distances ranging from 2.76–2.87 Å. There are two inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to six Te2- atoms to form GaTe6 octahedra that share corners with two equivalent CuTe6 octahedra, corners with four equivalent GaTe6 octahedra, edges with four equivalent GaTe6 octahedra, and edges with eight CuTe6 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. There are a spread of Ga–Te bond distances ranging from 2.86–2.92 Å. In the second Ga3+ site, Ga3+ is bonded to six Te2- atoms to form GaTe6 octahedra that share corners with two equivalent CuTe6 octahedra, corners with four equivalent GaTe6 octahedra, edges with four equivalent GaTe6 octahedra, and edges with eight CuTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Ga–Te bond distances ranging from 2.86–2.93 Å. There are four inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to three Cu1+ and three Ga3+ atoms to form a mixture of edge and corner-sharing TeGa3Cu3 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. In the second Te2- site, Te2- is bonded to three Cu1+ and three Ga3+ atoms to form a mixture of edge and corner-sharing TeGa3Cu3 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. In the third Te2- site, Te2- is bonded to three Cu1+ and three Ga3+ atoms to form a mixture of edge and corner-sharing TeGa3Cu3 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. In the fourth Te2- site, Te2- is bonded to three Cu1+ and three Ga3+ atoms to form a mixture of edge and corner-sharing TeGa3Cu3 octahedra. The corner-sharing octahedra tilt angles range from 1–3°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu4Bi4S9 by Materials Project

Cu4Bi4S9 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are four inequivalent Cu+1.50+ sites. In the first Cu+1.50+ site, Cu+1.50+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with four equivalent BiS5 square pyramids, corners with two equivalent CuS4 tetrahedra, and an edgeedge with one BiS5 square pyramid. There are a spread of Cu–S bond distances ranging from 2.29–2.36 Å. In the second Cu+1.50+ site, Cu+1.50+ is bonded in a distorted trigonal planar geometry to four S2- atoms. There are a spread of Cu–S bond distances ranging from 2.23–3.06 Å. In the third Cu+1.50+ site, Cu+1.50+ is bonded to four S2- atoms to form distorted CuS4 trigonal pyramids that share corners with three equivalent BiS6 octahedra, corners with two equivalent CuS4 trigonal pyramids, and edges with two equivalent CuS4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 2–77°. There are a spread of Cu–S bond distances ranging from 2.26–2.61 Å. In the fourth Cu+1.50+ site, Cu+1.50+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two equivalent BiS6 octahedra, a cornercorner with one BiS5 square pyramid, corners with two equivalent CuS4 tetrahedra, and an edgeedge with one BiS6 octahedra. The corner-sharing octahedral tilt angles are 30°. There are a spread of Cu–S bond distances ranging from 2.27–2.41 Å. There are four inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to five S2- atoms to form distorted BiS5 square pyramids that share corners with five CuS4 tetrahedra, edges with two equivalent BiS5 square pyramids, and an edgeedge with one CuS4 tetrahedra. There are a spread of Bi–S bond distances ranging from 2.61–3.07 Å. In the second Bi3+ site, Bi3+ is bonded in a 5-coordinate geometry to seven S2- atoms. There are a spread of Bi–S bond distances ranging from 2.65–3.44 Å. In the third Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Bi–S bond distances ranging from 2.69–3.13 Å. In the fourth Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with two equivalent CuS4 tetrahedra, corners with three equivalent CuS4 trigonal pyramids, edges with four equivalent BiS6 octahedra, and an edgeedge with one CuS4 tetrahedra. There are a spread of Bi–S bond distances ranging from 2.73–3.01 Å. There are nine inequivalent S2- sites. In the first S2- site, S2- is bonded to two Cu+1.50+ and two equivalent Bi3+ atoms to form corner-sharing SCu2Bi2 tetrahedra. In the second S2- site, S2- is bonded in a 3-coordinate geometry to two equivalent Cu+1.50+ and three Bi3+ atoms. In the third S2- site, S2- is bonded in a 4-coordinate geometry to one Cu+1.50+ and three Bi3+ atoms. In the fourth S2- site, S2- is bonded in a 6-coordinate geometry to three Cu+1.50+ and three Bi3+ atoms. In the fifth S2- site, S2- is bonded to three equivalent Cu+1.50+ and three Bi3+ atoms to form distorted edge-sharing SCu3Bi3 octahedra. In the sixth S2- site, S2- is bonded in a 1-coordinate geometry to one Cu+1.50+ and four Bi3+ atoms. In the seventh S2- site, S2- is bonded in a 5-coordinate geometry to five Bi3+ atoms. In the eighth S2- site, S2- is bonded in a 4-coordinate geometry to three Cu+1.50+ and one S2- atom. The S–S bond length is 2.15 Å. In the ninth S2- site, S2- is bonded in a 4-coordinate geometry to one Cu+1.50+, two equivalent Bi3+, and one S2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Tailoring composition and deformation modes at the microstructural level for next generation low-cost high-strength austenitic stainless steels

The objective of this project is to enable deliberate development of cost-effective, hydrogen resistant alloys by establishing detailed relationships specific to the effects of alloy composition, short-range order (SRO), and microsegregation in the presence of hydrogen on the transition between homogeneous deformation and localized plasticity in shear bands. In collaboration with the International Institute for Carbon-Neutral Energy Research, I2CNER, at Kyushu University in Japan, we conceptualized, designed, and manufactured four austenitic alloys that maintain corrosion resistance and ensure lower cost relative to baseline commercial alloys. The mechanical properties and deformation modes of the novel alloys (KU alloys) were assessed in the presence of hydrogen (H). Correlations between composition and performance revealed that two of the KU alloys are suitable replacements for 316 steel, while another is a viable replacement for 304 steel at room temperature. We found that, in the presence of other austenite stabilizing elements namely Mn and N, replacing Ni with Cu does not lead to martensite formation as has been previously reported.1–3 Furthermore, we found that the addition of Cu leads to an earlier onset of multiple slip resulting in an relative earlier onset of a higher work hardening rate (WHR). Greater understanding of the relationships between alloy composition and SRO required the development of a novel advanced electron diffraction methodology to characterize SRO in complex FCC alloys. This innovative approach, which combines fluctuation and correlation analyses of diffuse-scattering signals, successfully differentiated between SRO and long-range ordering (LRO). Further investigations into annealed austenitic stainless steels could provide insights into manipulating SRO and its effects on material properties. Atomistic simulations provided understanding of SRO behavior that was difficult to capture experimentally. This project created the first spin cluster expansion model that is able to capture and describe SRO effects in Fe-Ni-Cr FCC alloys, accounting for the non-negligible effects of magnetism. An automated computational workflow was established to provide reliable predictions of SRO in Fe-Ni-Cr austenitic alloys, both with and without the presence of H atoms. Analysis of the propensity for SRO in Fe-Ni-Cr alloys revealed that H tends to cluster with specific, well-defined SRO domains. The computational framework is general purpose and can be extended to realistic stainless steels across diverse composition ranges. With confidence that SRO is possible in austenitic stainless steels, we developed a discrete dislocation finite element code to understand the interaction of dislocations with SRO in the presence of H. By incorporating H effects on the dislocation emission and SRO stress field we show that the critical stress for the dislocation pileup to breakthrough the SRO domain decreases in the presence of H, which directly contributes localized deformation at the macroscale. Through the simulation of a uniaxial tension test, we demonstrated that H-induced weakening of SRO stress field and H-enhanced dislocation emission can lead to the onset of shear localization at lower macroscopic strains. As a whole, this project identified three novel alloys that show improvements in performance and cost efficiency for H-facing applications by studying correlations between alloy chemistry and deformation behavior. We also made significant advancements to experimental and computational methodologies necessary to study the chemistry and distribution of SRO across a range of alloys, which in turn allowed us to demonstrate how deformation mechanisms change due to the contributions of SRO in austenitic alloys in the presence of H. The combined advancements in fundamental understanding with novel alloy development in this project has increased the viability of next generation H-technologies for the broader public through accessible low-cost alloys and accelerated development towards future H-infrastructure.

08 HYDROGEN↗
DOE OSTI2025

Additively-manufactured Al-0.3Zr-0.2Ce-0.2Cu alloy with high creep resistance and electrical conductivity

Here, a new, solute-lean Al-0.3Zr-0.2Ce-0.2Cu (wt.%) alloy is developed for additive manufacturing that overcomes the classical tradeoff between conductivity and creep resistance. The rapid-cooling-enabled supersaturation of Zr, and its uniform distribution in α-Al matrix, along with formation of submicron (Ce,Cu)-rich intermetallic particles on solidification lead to unusually high creep resistance at 200 °C. Near-zero secondary creep rates are achieved up to the alloy yield stress (YS) of 65 MPa at 200 °C in as-fabricated state. The Zr-solute-induced dislocation-climb suppression mechanism underlying this improvement also restricts dynamic recovery above YS, as noted from appreciable primary creep and its transitioning to near-zero secondary creep rates. A combination of relatively coarse, epitaxially-grown α-Al grains, low Zr concentration in α-Al, and the impurity-scavenging effect of Ce to purify α-Al matrix produces high electrical conductivity of ∼48 %IACS. Aging precipitation of L1 2 -Al 3 Zr nanoprecipitates doubles the YS (to ∼150 MPa) at room temperature and increases alloy conductivity to ∼58 %IACS, but loss of solid-solution Zr out of α-Al matrix leads to activation of dislocation climb, degrading the creep properties as compared to the supersaturated Al-Zr solid solution in the as-fabricated state. Compared to L1 2 -Al 3 Zr nanoprecipitates, submicron (Ce,Cu)-rich particles formed on solidification are more effective at impeding dislocation climb, producing a threshold stress for dislocation creep of ∼ 50 MPa at 200 °C. The new alloy design concepts, especially solute-induced dislocation-climb suppression for creep resistance, explored here may pave way for the design of new metallic alloys for thermal/electrical conductors and other high-temperature applications.

Additive Manufacturing↗
NASA NTRS2007

Critical Issues for Cu(InGa)Se2 Solar Cells on Flexible Polymer Web

Elemental in-line evaporation on glass substrates has been a viable process for the large-area manufacture of CuInSe2-based photovoltaics, with module efficiencies as high as 12.7% [1]. However, lightweight, flexible CuInSe2-based modules are attractive in a number of applications, such as space power sources. In addition, flexible substrates have an inherent advantage in manufacturability in that they can be deposited in a roll-to-roll configuration allowing continuous, high yield, and ultimately lower cost production. As a result, high-temperature polymers have been used as substrates in depositing CuInSe2 films [2]. Recently, efficiency of 14.1% has been reported for a Cu(InGa)Se2-based solar cell on a polyimide substrate [3]. Both metal foil and polymer webs have been used as substrates for Cu(InGa)Se2-based photovoltaics in a roll-to-roll configuration with reasonable success [4,5]. Both of these substrates do not allow, readily, the incorporation of Na into the Cu(InGa)Se2 film which is necessary for high efficiency devices [3]. In addition, polymer substrates, can not be used at temperatures that are optimum for Cu(InGa)Se2 deposition. However, unlike metal foils, they are electrically insulating, simplifying monolithically-integrated module fabrication and are not a source of impurities diffusing into the growing film. The Institute of Energy Conversion (IEC) has modified its in-line evaporation system [6] from deposition onto glass substrates to roll-to-roll deposition onto polyimide (PI) film in order to investigate key issues in the deposition of large-area Cu(InGa)Se2 films on flexible polymer substrates. This transition presented unexpected challenges that had to be resolved. In this paper, two major problems, spitting from the Cu source and the cracking of Mo back contact film, will be discussed and the solution to each will be presented.

Eser, Erten↗
DOE OSTI2020

Materials Data on Cu11Sb4S13 by Materials Project

Cu11Sb4S13 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are seven inequivalent Cu+1.09+ sites. In the first Cu+1.09+ site, Cu+1.09+ is bonded in a distorted trigonal planar geometry to three S2- atoms. There are a spread of Cu–S bond distances ranging from 2.24–2.30 Å. In the second Cu+1.09+ site, Cu+1.09+ is bonded in a distorted trigonal planar geometry to three S2- atoms. There are a spread of Cu–S bond distances ranging from 2.25–2.32 Å. In the third Cu+1.09+ site, Cu+1.09+ is bonded in a distorted trigonal planar geometry to three S2- atoms. There are one shorter (2.20 Å) and two longer (2.31 Å) Cu–S bond lengths. In the fourth Cu+1.09+ site, Cu+1.09+ is bonded to four S2- atoms to form corner-sharing CuS4 tetrahedra. There are a spread of Cu–S bond distances ranging from 2.27–2.36 Å. In the fifth Cu+1.09+ site, Cu+1.09+ is bonded in a distorted T-shaped geometry to three S2- atoms. There are two shorter (2.25 Å) and one longer (2.30 Å) Cu–S bond lengths. In the sixth Cu+1.09+ site, Cu+1.09+ is bonded to four S2- atoms to form corner-sharing CuS4 tetrahedra. There are a spread of Cu–S bond distances ranging from 2.29–2.31 Å. In the seventh Cu+1.09+ site, Cu+1.09+ is bonded in a trigonal planar geometry to three S2- atoms. There are a spread of Cu–S bond distances ranging from 2.25–2.32 Å. There are three inequivalent Sb+3.50+ sites. In the first Sb+3.50+ site, Sb+3.50+ is bonded in a distorted T-shaped geometry to three S2- atoms. There are two shorter (2.45 Å) and one longer (2.52 Å) Sb–S bond lengths. In the second Sb+3.50+ site, Sb+3.50+ is bonded in a distorted T-shaped geometry to three S2- atoms. There are one shorter (2.45 Å) and two longer (2.49 Å) Sb–S bond lengths. In the third Sb+3.50+ site, Sb+3.50+ is bonded in a distorted T-shaped geometry to three S2- atoms. There are one shorter (2.48 Å) and two longer (2.51 Å) Sb–S bond lengths. There are eight inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to two Cu+1.09+ and one Sb+3.50+ atom. In the second S2- site, S2- is bonded to six Cu+1.09+ atoms to form corner-sharing SCu6 octahedra. In the third S2- site, S2- is bonded to three Cu+1.09+ and one Sb+3.50+ atom to form distorted SCu3Sb tetrahedra that share a cornercorner with one SCu6 octahedra and corners with four SCu3Sb tetrahedra. The corner-sharing octahedral tilt angles are 46°. In the fourth S2- site, S2- is bonded in a 4-coordinate geometry to three Cu+1.09+ and one Sb+3.50+ atom. In the fifth S2- site, S2- is bonded in a trigonal non-coplanar geometry to two Cu+1.09+ and one Sb+3.50+ atom. In the sixth S2- site, S2- is bonded to three Cu+1.09+ and one Sb+3.50+ atom to form SCu3Sb tetrahedra that share a cornercorner with one SCu6 octahedra and corners with three SCu3Sb tetrahedra. The corner-sharing octahedral tilt angles are 53°. In the seventh S2- site, S2- is bonded to three Cu+1.09+ and one Sb+3.50+ atom to form distorted SCu3Sb tetrahedra that share a cornercorner with one SCu6 octahedra and corners with four SCu3Sb tetrahedra. The corner-sharing octahedral tilt angles are 38°. In the eighth S2- site, S2- is bonded in a trigonal non-coplanar geometry to two Cu+1.09+ and one Sb+3.50+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Cu-Doped Iron Oxide for the Efficient Electrocatalytic Nitrate Reduction Reaction

The electrochemical nitrate reduction reaction (NO 3 RR) is a promising alternative synthetic route for sustainable ammonia (NH 3 ) production, because it not only eliminates nitrate (NO 3 – ) from water but also produces NH 3 under mild operating conditions. However, owing to the complicated eight-electron reaction and the competition from the hydrogen evolution reaction, developing catalysts with high activities and Faradaic efficiencies (FEs) is highly imperative to improve the reaction performance. In this study, Cu-doped Fe 3 O 4 flakes are fabricated and demonstrated to be excellent catalysts for electrochemical conversion of NO 3 – to NH 3 , with a maximum FE of ~100% and an NH 3 yield of 179.55 ± 16.37 mg h –1 mg cat –1 at –0.6 V vs RHE. Here, theoretical calculations reveal that doping the catalyst surface with Cu results in a more thermodynamically facile reaction. These results highlight the feasibility of promoting the NO 3 RR activity using heteroatom doping strategies.

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

Materials Data on Na4V20(CuO4)15 by Materials Project

Na4V20(CuO4)15 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are two inequivalent Na sites. In the first Na site, Na is bonded to twelve O atoms to form NaO12 cuboctahedra that share faces with eight VO6 octahedra. There are a spread of Na–O bond distances ranging from 2.60–2.63 Å. In the second Na site, Na is bonded to twelve O atoms to form NaO12 cuboctahedra that share faces with eight VO6 octahedra. There are a spread of Na–O bond distances ranging from 2.61–2.63 Å. There are six inequivalent V sites. In the first V site, V is bonded to six O atoms to form VO6 octahedra that share corners with six VO6 octahedra and a faceface with one NaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 40°. There is three shorter (1.95 Å) and three longer (1.98 Å) V–O bond length. In the second V site, V is bonded to six O atoms to form VO6 octahedra that share corners with six VO6 octahedra and faces with two NaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 38–41°. There is three shorter (1.92 Å) and three longer (1.93 Å) V–O bond length. In the third V site, V is bonded to six equivalent O atoms to form VO6 octahedra that share corners with six equivalent VO6 octahedra and faces with two equivalent NaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 40°. All V–O bond lengths are 1.93 Å. In the fourth V site, V is bonded to six O atoms to form VO6 octahedra that share corners with six VO6 octahedra and faces with two NaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 38–41°. There are a spread of V–O bond distances ranging from 1.93–1.98 Å. In the fifth V site, V is bonded to six O atoms to form VO6 octahedra that share corners with six VO6 octahedra and a faceface with one NaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 39–41°. There are a spread of V–O bond distances ranging from 1.86–2.02 Å. In the sixth V site, V is bonded to six O atoms to form VO6 octahedra that share corners with six VO6 octahedra and faces with two equivalent NaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 39–41°. There is two shorter (1.95 Å) and four longer (1.96 Å) V–O bond length. There are three inequivalent Cu sites. In the first Cu site, Cu is bonded in a square co-planar geometry to four O atoms. There is two shorter (1.92 Å) and two longer (1.93 Å) Cu–O bond length. In the second Cu site, Cu is bonded in a square co-planar geometry to four O atoms. There are a spread of Cu–O bond distances ranging from 1.92–1.95 Å. In the third Cu site, Cu is bonded in a square co-planar geometry to four O atoms. There are a spread of Cu–O bond distances ranging from 1.93–1.96 Å. There are ten inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to one Na, two V, and one Cu atom. In the second O site, O is bonded in a 4-coordinate geometry to one Na, two V, and one Cu atom. In the third O site, O is bonded in a 3-coordinate geometry to one Na, two V, and one Cu atom. In the fourth O site, O is bonded in a 4-coordinate geometry to one Na, two V, and one Cu atom. In the fifth O site, O is bonded in a 4-coordinate geometry to one Na, two V, and one Cu atom. In the sixth O site, O is bonded in a 4-coordinate geometry to one Na, two V, and one Cu atom. In the seventh O site, O is bonded in a distorted trigonal planar geometry to two equivalent V and one Cu atom. In the eighth O site, O is bonded in a 3-coordinate geometry to one Na, two V, and one Cu atom. In the ninth O site, O is bonded in a 4-coordinate geometry to one Na, two V, and one Cu atom. In the tenth O site, O is bonded in a distorted trigonal planar geometry to two V and one Cu atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CoCu3(PO4)4 by Materials Project

CoCu3(PO4)4 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. Co4+ is bonded to six O2- atoms to form distorted CoO6 pentagonal pyramids that share corners with four PO4 tetrahedra and an edgeedge with one PO4 tetrahedra. There are a spread of Co–O bond distances ranging from 1.94–2.31 Å. There are three inequivalent Cu+2.67+ sites. In the first Cu+2.67+ site, Cu+2.67+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There is three shorter (1.87 Å) and one longer (1.89 Å) Cu–O bond length. In the second Cu+2.67+ site, Cu+2.67+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There is two shorter (1.84 Å) and two longer (1.90 Å) Cu–O bond length. In the third Cu+2.67+ site, Cu+2.67+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There is three shorter (1.86 Å) and one longer (1.87 Å) Cu–O bond length. There are four 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 CoO6 pentagonal pyramid. There are a spread of P–O bond distances ranging from 1.53–1.56 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CoO6 pentagonal pyramid and an edgeedge with one CoO6 pentagonal pyramid. There are a spread of P–O bond distances ranging from 1.51–1.59 Å. In the third P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of P–O bond distances ranging from 1.54–1.56 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CoO6 pentagonal pyramids. There is one shorter (1.55 Å) and three longer (1.56 Å) P–O bond length. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Co4+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu+2.67+ and one P5+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Cu+2.67+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cu+2.67+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Co4+, one Cu+2.67+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cu+2.67+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cu+2.67+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu+2.67+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Co4+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cu+2.67+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Co4+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu+2.67+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu3Ag5(PO4)4 by Materials Project

Ag5Cu3(PO4)4 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ag–O bond distances ranging from 2.43–3.09 Å. In the second Ag1+ site, Ag1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ag–O bond distances ranging from 2.33–3.04 Å. In the third Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ag–O bond distances ranging from 2.23–2.90 Å. There are two inequivalent Cu+2.33+ sites. In the first Cu+2.33+ site, Cu+2.33+ is bonded in a square co-planar geometry to four O2- atoms. There are two shorter (1.95 Å) and two longer (2.08 Å) Cu–O bond lengths. In the second Cu+2.33+ site, Cu+2.33+ is bonded to five O2- atoms to form CuO5 square pyramids that share corners with five PO4 tetrahedra. There are a spread of Cu–O bond distances ranging from 1.92–2.25 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 corners with two equivalent CuO5 square pyramids. There are a spread of P–O bond distances ranging from 1.55–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent CuO5 square pyramids. There are a spread of P–O bond distances ranging from 1.53–1.59 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Ag1+, one Cu+2.33+, and one P5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to three Ag1+, one Cu+2.33+, and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Ag1+, one Cu+2.33+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to three Ag1+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ag1+, two Cu+2.33+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Ag1+, one Cu+2.33+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two Ag1+, one Cu+2.33+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to four Ag1+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KCu2H2(SO5)2 by Materials Project

KCu2H2(SO5)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded to eight O2- atoms to form distorted KO8 hexagonal bipyramids that share corners with four equivalent SO4 tetrahedra, edges with four equivalent CuO6 octahedra, and edges with two equivalent SO4 tetrahedra. There are six shorter (2.82 Å) and two longer (2.96 Å) K–O bond lengths. Cu+2.50+ is bonded to six O2- atoms to form distorted CuO6 octahedra that share corners with four equivalent SO4 tetrahedra, edges with two equivalent KO8 hexagonal bipyramids, and edges with two equivalent CuO6 octahedra. There are a spread of Cu–O bond distances ranging from 1.89–2.50 Å. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with two equivalent KO8 hexagonal bipyramids, corners with four equivalent CuO6 octahedra, and an edgeedge with one KO8 hexagonal bipyramid. The corner-sharing octahedra tilt angles range from 42–50°. There are a spread of S–O bond distances ranging from 1.46–1.52 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one K1+, two equivalent Cu+2.50+, and one S6+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Cu+2.50+, and one S6+ atom. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Cu+2.50+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one K1+ and one S6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mn3Cu2Sn(PO4)6 by Materials Project

Mn3Cu2Sn(PO4)6 crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are three inequivalent Mn+3.67+ sites. In the first Mn+3.67+ site, Mn+3.67+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six PO4 tetrahedra. There is three shorter (1.93 Å) and three longer (2.02 Å) Mn–O bond length. In the second Mn+3.67+ site, Mn+3.67+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six PO4 tetrahedra. There is three shorter (1.88 Å) and three longer (1.95 Å) Mn–O bond length. In the third Mn+3.67+ site, Mn+3.67+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six PO4 tetrahedra. There is three shorter (1.93 Å) and three longer (2.00 Å) Mn–O bond length. There are two inequivalent Cu+1.50+ sites. In the first Cu+1.50+ site, Cu+1.50+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.17 Å) and three longer (2.26 Å) Cu–O bond lengths. In the second Cu+1.50+ site, Cu+1.50+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are three shorter (2.24 Å) and three longer (2.25 Å) Cu–O bond lengths. Sn4+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with six PO4 tetrahedra. There are three shorter (2.01 Å) and three longer (2.07 Å) Sn–O bond lengths. 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 SnO6 octahedra and corners with three MnO6 octahedra. The corner-sharing octahedra tilt angles range from 25–46°. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SnO6 octahedra and corners with three MnO6 octahedra. The corner-sharing octahedra tilt angles range from 26–47°. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Mn+3.67+ and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Mn+3.67+, one Cu+1.50+, and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Sn4+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Mn+3.67+, one Cu+1.50+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Mn+3.67+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Cu+1.50+, one Sn4+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Mn+3.67+, one Cu+1.50+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Mn+3.67+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La12Cu10O31 by Materials Project

La12Cu10O31 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are six inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.48–2.67 Å. In the second La3+ site, La3+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.36–2.73 Å. In the third La3+ site, La3+ is bonded in a distorted octahedral geometry to six O2- atoms. There are a spread of La–O bond distances ranging from 2.43–2.49 Å. In the fourth La3+ site, La3+ is bonded in a distorted octahedral geometry to six O2- atoms. There are a spread of La–O bond distances ranging from 2.27–2.55 Å. In the fifth La3+ site, La3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.47–2.67 Å. In the sixth La3+ site, La3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of La–O bond distances ranging from 2.32–2.62 Å. There are six inequivalent Cu+2.60+ sites. In the first Cu+2.60+ site, Cu+2.60+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.87–1.94 Å. In the second Cu+2.60+ site, Cu+2.60+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.87–1.94 Å. In the third Cu+2.60+ site, Cu+2.60+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There is two shorter (1.93 Å) and two longer (1.94 Å) Cu–O bond length. In the fourth Cu+2.60+ site, Cu+2.60+ is bonded in a T-shaped geometry to three O2- atoms. All Cu–O bond lengths are 1.79 Å. In the fifth Cu+2.60+ site, Cu+2.60+ is bonded in a square co-planar geometry to four O2- atoms. All Cu–O bond lengths are 1.93 Å. In the sixth Cu+2.60+ site, Cu+2.60+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.85–1.94 Å. There are seventeen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent La3+ and one Cu+2.60+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent La3+ and three Cu+2.60+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three La3+ and one Cu+2.60+ atom. In the fourth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three La3+ atoms. In the fifth O2- site, O2- is bonded in a distorted see-saw-like geometry to three La3+ and one Cu+2.60+ atom. In the sixth O2- site, O2- is bonded in a distorted see-saw-like geometry to three La3+ and one Cu+2.60+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two La3+ and three Cu+2.60+ atoms. In the eighth O2- site, O2- is bonded to three La3+ and one Cu+2.60+ atom to form distorted edge-sharing OLa3Cu trigonal pyramids. In the ninth O2- site, O2- is bonded in a distorted see-saw-like geometry to three La3+ and one Cu+2.60+ atom. In the tenth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three La3+ atoms. In the eleventh O2- site, O2- is bonded in a distorted see-saw-like geometry to three La3+ and one Cu+2.60+ atom. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to three La3+ and one Cu+2.60+ atom. In the thirteenth O2- site, O2- is bonded to two equivalent La3+ and three Cu+2.60+ atoms to form distorted corner-sharing OLa2Cu3 trigonal bipyramids. In the fourteenth O2- site, O2- is bonded to two La3+ and three Cu+2.60+ atoms to form distorted OLa2Cu3 trigonal bipyramids that share a cornercorner with one OLa2Cu3 trigonal bipyramid and an edgeedge with one OLa3Cu trigonal pyramid. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to three La3+ and one Cu+2.60+ atom. In the sixteenth O2- site, O2- is bonded in a distorted see-saw-like geometry to three La3+ and one Cu+2.60+ atom. In the seventeenth O2- site, O2- is bonded in a distorted see-saw-like geometry to three La3+ and one Cu+2.60+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li2Cu2F5 by Materials Project

Li2Cu2F5 is beta indium sulfide-derived structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to six F1- atoms to form edge-sharing LiF6 octahedra. There are a spread of Li–F bond distances ranging from 1.99–2.27 Å. In the second Li1+ site, Li1+ is bonded to six F1- atoms to form edge-sharing LiF6 octahedra. There are a spread of Li–F bond distances ranging from 1.98–2.10 Å. There are two inequivalent Cu+1.50+ sites. In the first Cu+1.50+ site, Cu+1.50+ is bonded in a distorted T-shaped geometry to three F1- atoms. There is two shorter (1.85 Å) and one longer (2.07 Å) Cu–F bond length. In the second Cu+1.50+ site, Cu+1.50+ is bonded in a distorted T-shaped geometry to three F1- atoms. There are a spread of Cu–F bond distances ranging from 1.85–1.98 Å. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded to three Li1+ and one Cu+1.50+ atom to form corner-sharing FLi3Cu trigonal pyramids. In the second F1- site, F1- is bonded in a rectangular see-saw-like geometry to three equivalent Li1+ and one Cu+1.50+ atom. In the third F1- site, F1- is bonded in a rectangular see-saw-like geometry to three Li1+ and one Cu+1.50+ atom. In the fourth F1- site, F1- is bonded in a distorted trigonal planar geometry to two equivalent Li1+ and one Cu+1.50+ atom. In the fifth F1- site, F1- is bonded in a 3-coordinate geometry to one Li1+ and two Cu+1.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on V4Cu13(O13F2)2 by Materials Project

V4Cu13(O13F2)2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent V5+ sites. In the first V5+ site, V5+ is bonded to four O2- atoms to form VO4 tetrahedra that share corners with four CuO6 octahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of V–O bond distances ranging from 1.67–1.84 Å. In the second V5+ site, V5+ is bonded to four O2- atoms to form VO4 tetrahedra that share corners with four CuO6 octahedra. The corner-sharing octahedra tilt angles range from 46–57°. There are a spread of V–O bond distances ranging from 1.65–1.86 Å. There are eight inequivalent Cu+2.77+ sites. In the first Cu+2.77+ site, Cu+2.77+ is bonded to six O2- atoms to form distorted CuO6 octahedra that share corners with four VO4 tetrahedra and edges with four CuO6 octahedra. There are a spread of Cu–O bond distances ranging from 1.87–2.50 Å. In the second Cu+2.77+ site, Cu+2.77+ is bonded to six O2- atoms to form distorted CuO6 octahedra that share corners with four VO4 tetrahedra and edges with four CuO6 octahedra. There are a spread of Cu–O bond distances ranging from 1.85–2.58 Å. In the third Cu+2.77+ site, Cu+2.77+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with four VO4 tetrahedra and edges with two CuO6 octahedra. There are a spread of Cu–O bond distances ranging from 1.87–2.39 Å. In the fourth Cu+2.77+ site, Cu+2.77+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Cu–O bond distances ranging from 1.85–2.64 Å. In the fifth Cu+2.77+ site, Cu+2.77+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.84–1.91 Å. In the sixth Cu+2.77+ site, Cu+2.77+ is bonded in a 6-coordinate geometry to four O2- and two equivalent F1- atoms. There are a spread of Cu–O bond distances ranging from 1.88–2.44 Å. There are one shorter (1.87 Å) and one longer (2.42 Å) Cu–F bond lengths. In the seventh Cu+2.77+ site, Cu+2.77+ is bonded in a 6-coordinate geometry to four O2- and two F1- atoms. There are a spread of Cu–O bond distances ranging from 1.88–1.97 Å. There are one shorter (2.39 Å) and one longer (2.51 Å) Cu–F bond lengths. In the eighth Cu+2.77+ site, Cu+2.77+ is bonded in a distorted square co-planar geometry to four O2- and two equivalent F1- atoms. There are two shorter (1.82 Å) and two longer (2.52 Å) Cu–O bond lengths. Both Cu–F bond lengths are 1.82 Å. There are thirteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one V5+ and two Cu+2.77+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one V5+ and two Cu+2.77+ atoms. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one V5+ and two Cu+2.77+ atoms. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one V5+ and two Cu+2.77+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one V5+ and two equivalent Cu+2.77+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one V5+ and three Cu+2.77+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one V5+ and two Cu+2.77+ atoms. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to one V5+ and two Cu+2.77+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Cu+2.77+ atoms. In the tenth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Cu+2.77+ atoms. In the eleventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Cu+2.77+ atoms. In the twelfth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Cu+2.77+ atoms. In the thirteenth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Cu+2.77+ atoms. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a 1-coordinate geometry to three Cu+2.77+ atoms. In the second F1- site, F1- is bonded in a distorted single-bond geometry to two Cu+2.77+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Phase change material integrated core–shell catalyst for in situ thermal control in methanol synthesis from syngas

A model-guided core–shell catalyst design is presented for methanol synthesis, featuring a phase change material (PCM) core encapsulated by a Cu–Zn–Al 2 O 3 (CZA) catalytic shell. The PCM enables in situ thermal management by absorbing reaction heat at its melting point, mitigates the kinetic decline at high temperatures and therefore avoids low conversion, prevents hot spots, and stabilizes the reaction temperature. A two-dimensional axisymmetric, non-isothermal packed-bed reactor model (COMSOL 6.3) was developed for a 10 g system. Simulations evaluate three PCM candidates, that is, LiNO 3 , 9 wt% LiCl + 91 wt% LiNO 3 , and commercial H250, with melting points near 244–250°C. Results indicate that CO conversion can increase from 34.4% to 52.4%, and methanol production can improve by 69% compared to a conventional packed-bed reactor. Beyond methanol synthesis, the PCM-integrated core–shell concept provides a scalable approach for thermal control in exothermic reactions, improving reactor efficiency and safety.

core–shell catalyst↗
DOE OSTI2023

Effect of Flexibility in Molecular Simulations of Carbon Dioxide Adsorption and Diffusion in a Cuprous Triazolate Framework

Using fixed atom force fields to model gas adsorption in flexible metal organic frameworks (MOFs) is known to pose difficulties in accurately reproducing and predicting experimental results. This paper studies the difference in accuracy between flexible and fixed atom force fields in reproducing CO 2 adsorption measurements in MAF-2 ([Cu(etz)]∞ (MAF-2, Hetz) 3,5-diethyl-1,2,4-triazole), an NbO-type triazolate scaffold with a bcu cavity system and attached ethyl groups. The flexible force field used to run the hybrid molecular dynamics and grand canonical Monte Carlo calculations were generated using the QuickFF software incorporating van der Waals parameters from the Universal Force Field (UFF) and density derived electrostatic and chemical (DDEC) charges. The fixed atom force field used was composed of UFF van der Waals parameters together with DDEC charges. The calculations were run at 298 K and at pressures of 0.1, 0.3, 0.5, 0.8, and 1 bar. It was observed that for this MOF the rigid force field overpredicted gas adsorption, whereas the flexible force field values closely matched experimental data. In the flexible structure, the freely moving ethyl groups of MAF-2 hindered adsorption, reducing the interaction energy between CO 2 and the N atoms of the triazolate framework as well as reducing the size of the largest cavity diameter. Here, the combination of these factors led to improved prediction of adsorption values with the flexible forcefield as compared to the rigid forcefield, demonstrating the need for modeling MOFs in a way more indicative of their behavior.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

When Do Band Gap Calculations Agree with Experiments in Monolayer-Protected Cu 14 and Au 20 Atomically Precise Nanoclusters? A (TD)-DFT Comparison of HOMO–LUMO, Fundamental, Optical, and Electrochemical Energy Gaps

In view of the tremendous progress in atomically precise metal nanoclusters where electrochemical and optical energetics are routinely supported by computations to establish structure−function correlations, we explore the relationship between different protocols for measuring and computing band gaps of two distinct organic ligand-protected nanoclusters: [Cu 14 H 10 (MBN) 3 (PPh 3 ) 8 ] + and Au 20 (TBBT) 16 . Through UV/visible spectroscopy and differential pulse voltammetry, we measure optical and electrochemical band gaps in those systems. We then compare these experimentally determined gaps to HOMO−LUMO gaps, fundamental gaps, vertical excitation energies, and E o ox − E o red potentials computed using different density functional theory (DFT) or time-dependent DFT (TDDFT) methods. Specifically, in both copper and gold nanoclusters, we test the effect of truncating inert ligands from the model and compare density functionals with varying degrees of Hartree−Fock (HF) exchange from 0 to 50%, range-separated hybrids with a varying long-range tuning parameter, different correlation functionals, basis sets, and (equilibrium and nonequilibrium) continuum solvation models. Despite having different frontier orbital characters (the copper nanocluster has a metal-to-ligand charge transfer character while the gold nanocluster has metal-centered frontier orbitals), both nanoclusters display a similar sensitivity of the HOMO−LUMO gap to the HF exchange that is partially mitigated when computing the fundamental, optical, and electrochemical gaps. Other factors, such as the nature of the correlation functional, basis set, and geometry relaxation, have a considerably smaller effect on computed band gaps in these systems. Overall, this work provides guidelines for factors of varied importance for correlating computed and experimental band gap values.

Chemical calculations↗