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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Cascade CO 2 Insertion in Carbanion Ionic Liquids Driven by Structure Rearrangement

The CO 2 chemisorption in state-of-the-art sorbents based on oxide/hydroxide/amine moieties is driven by strong chemical bonding formation in the carbonate/bicarbonate/carbamate products, which in turn leads to high energy input in sorbent regeneration. In addition, the CO 2 uptake capacity was limited by the active sites’ utilization efficiency, with each active site incorporating one CO 2 molecule or less. In this work, a new concept and generation of sorbent was developed to achieve cascade insertion of multiple CO 2 molecules by leveraging structure rearrangement as the driving force, leading to in situ generation of extra CO 2 -binding sites and significantly reduced energy input for CO 2 release. The designed ionic liquids (ILs) containing carbanions with conjugated and asymmetric structure, deprotonated (methylsulfonyl)acetonitrile ([MSA]) anion, allowed the cascade insertion of two CO 2 molecules via consecutive C–C and O–C bond formations. The proton transfer and structure rearrangement of the carboxylic acid intermediates played critical roles in stabilizing the first integrated CO 2 and generating extra electron-rich oxygen sites for the insertion of the second CO 2 . The structure variation and reaction pathway were confirmed by operando spectroscopy, magnetic resonance spectroscopy (NMR), mass spectroscopy, and computational chemistry. The energy input in sorbent regeneration could be further reduced by harnessing the phase-changing behavior of the carbanion salts in ether solutions upon reacting with CO 2 , avoiding the energy consumption in heating the solvent. In conclusion, the fundamental insights obtained herein provide a promising approach to greatly improve the CO 2 sorption performance via sophisticated molecular-scale structural engineering of the sorbents.

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

Search For Excited Cascade Hypersons (¿*-) Using the CLAS12 Spectrometer at Jefferson Laboratory

The number of experimentally observed doubly strange Cascade states to date is far fewer than has been predicted theoretically. The CLAS12 Very Strange physics program (E12- 11-005A) at the Thomas Jefferson National Accelerator Facility aims to study the electroproduction of these states using the newly upgraded CEBAF Large Acceptance Spectrometer for 12 GeV (CLAS12) in experimental Hall B. In this project, the reaction ep ! e0K+K+??? ! e0K+K+K?(?=?0) is studied using CLAS12 Run Group A (RG-A) data sets taken by impinging electron beams of 10:2 and 10:6 GeV energies on an LH2 target. Scattered electrons are detected with either the Forward Detector (FD), covering a polar angle range of 5? to 35? to study electroproduction, or with the Forward Tagger (FT), covering a polar angle range of 2:5? to 4:5?, to study quasi-real photoproduction. The CLAS12 detector with nearly a 4? solid angle coverage is used to detect scattered electrons and charged kaons in the ?final state. ?=?0 hyperons are reconstructed using the missing mass technique to explore intermediate doubly-strange hyperons (???) that decay to K? and ?=?0. No statistically significant ??? states other than the ???(1530) were found in the missing mass spectra based on the currently available statistics in the CLAS12-FD acceptance only. A maximum log-likelihood method is implemented to determine the statistical significance and the upper limits on the ???(1820) electroproduction cross section by constructing 95% confidence level boundaries on the ???(1820) yields. Additional research was conducted to investigate the upper limit electroproduction cross section of the reaction ep ! e0K+K+??? ! e0K+K+K?(?=?0) as a function of the electroproduced ??? mass and the differential cross section ( d?dMM(e0K+K+) ) as a function of missing mass MM(e0K+K+) for electroproduction and quasi-real photoproduction processes.

Khanal, Achyut↗
DOE OSTI2022

Charged particle motion and radiation in strong electromagnetic fields

The dynamics of charged particles in electromagnetic fields is an essential component of understanding the most extreme environments in our Universe. In electromagnetic fields of sufficient magnitude, radiation emission dominates the particle motion and effects of quantum electrodynamics (QED) in strong fields are crucial, which triggers electron-positron pair cascades and counterintuitive particle-Trapping phenomena. As a result of recent progress in laser technology, high-power lasers provide a platform to create and probe such fields in the laboratory. With new large-scale laser facilities on the horizon and the prospect of investigating these hitherto unexplored regimes, this review explores the basic physical processes of radiation reaction and QED in strong fields, how they are treated theoretically and in simulation, the new collective dynamics they unlock, recent experimental progress and plans, and possible applications for high-flux particle and radiation sources.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2026

Synergy and antagonism in a genome-scale model of metabolic hijacking by bacteriophages

Bacteriophage auxiliary metabolic genes (AMGs) alter host metabolism by hijacking reactions, but previous studies mostly inferred their roles from annotations, ignoring system-wide impacts and phage production. Here we integrate AMGs and phage assembly into a genome-scale metabolic model of Prochloroccocus marinus MED4 infected by P-HM2. We show that 17 directly hijacked reactions substantially affect more than 30% of the reactions in MED4 metabolism, including carbon fixation, photosynthesis, and nucleotide synthesis, distinguishing these AMGs as either phage aligned—shifting feasible reaction velocities in accordance with maximal phage production—or phage antialigned. Pareto optimization reveals that phage-aligned reactions alter phage-host growth trade-offs, while phage-antialigned reactions do not. We experimentally validate our predictions of system-level AMG impacts by measuring the N-dependent effect of P-HM2 cp12 expression on growth in a model relative of the genetically intractable MED4, Synechococcus elongatus. We also show that AMGs’ indirect impacts are synergistically and antagonistically coupled, providing systems-level insight into AMG perturbations and highlighting how nontrivial cascading effects shape host metabolism.

Rozum, Jordan C. [Pacific Northwest National Labor↗
DOE OSTI2022

Single-particle and collective excitations in Zn 66

Single-particle and collective excitations in 66 Zn have been investigated via the multinucleon transfer reaction, 26 Mg( 48 Ca, α4nγ) using the Gammasphere multidetector array and the Fragment Mass Analyzer. In addition to confirming and complementing the previously known low-spin structure, a new quasi-rotational band comprising several stretched E2 transitions has been established to high spins. However, due to fragmentary nature of its decay, it was not possible to link this sequence to the low-lying states and, thus, determine the absolute excitation energies, spins, and parities unambiguously. Large-scale shell-model calculations employing the JUN45 and jj44b effective interactions are able to successfully describe the low-spin structure and herewith confirm that it is dominated by single-particle excitations. Furthermore, the newly established rotational cascade is compared with known superdeformed bands in the A ≈ 60–70 mass region, and with results of calculations performed within the frameworks of the cranked shell model and the adiabatic and configuration-fixed constrained covariant density functional theory and the quantum particle-rotor model.

59 ≤ A ≤ 89↗
DOE OSTI2025

Plasmonic pathway to hybrid nanomaterials through energy transfer

Plasmon-induced resonance energy transfer (PIRET) is a promising approach for plasmonic photocatalysis and energy conversion, but challenges include elucidating the mechanism and maximizing its efficiency, both of which are hampered by competing processes. Another challenge is demonstrating that PIRET can photoinitiate reactions that follow efficient pathways compared to bulk processes. We report a plasmon-induced route to plasmonic-polymer hybrid nanomaterials using in operando single-particle spectroelectrochemistry. An energy transfer efficiency of 40% is achievable when the spectral overlap between gold nanorod scattering and polymer absorption is maximized. We also show that PIRET-initiated polymerization proceeds through a different mechanism than bulk polymerization, supported by spectroscopic evidence and density functional theory calculations, highlighting efficient energy cascading from photon to plasmon to exciton and, lastly, to unconventional light-initiated chemistry.

Oh, Hyuncheol [University of Illinois Urbana-Champ↗
DOE OSTI2026

Catalytic Reaction Intermediates Revealed with Femtosecond M-edge XANES (Final Technical Report)

The major goals of this work were to measure the electronic structure of earth-abundant catalysts at key steps in their catalytic cycles using ultrafast UV/Visible, Extreme Ultraviolet, and X-ray spectroscopy. Our central idea was that by using these sophisticated probes, we could uncover hidden reaction mechanisms and provide guidance for catalyst design. A second major goal was the development of Extreme Ultraviolet (XUV) spectroscopy as an accessible, tabletop probe of transition metal electronic structure. Spectra in this 30-100 eV energy range probe 3d→3p transitions in 3d metals and 5p/4f→5d transitions in 5d metals, and share the oxidation state, spin state, and ligand field specificity of hard X-ray spectroscopy. The Vura-Weis group previously established the basic utility of this technique for measuring the excited-state cascades of transition metal chromophores, and in this grant we intended to extend its scope to catalytic intermediates.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Reductive amination cascades in cell‐free and resting whole cell formats for valorization of lignin deconstruction products

Abstract The selective introduction of amine groups within deconstruction products of lignin could provide an avenue for valorizing waste biomass while achieving a green synthesis of industrially relevant building blocks from sustainable sources. Here, we built and characterized enzyme cascades that create aldehydes and subsequently primary amines from diverse lignin‐derived carboxylic acids using a carboxylic acid reductase (CAR) and an ω‐transaminase (TA). Unlike previous studies that have paired CAR and TA enzymes, here we examine multiple homologs of each of these enzymes and a broader set of candidate substrates. In addition, we compare the performance of these systems in cell‐free and resting whole‐cell biocatalysis formats using the conversion of vanillate to vanillyl amine as model chemistry. We also demonstrate that resting whole cells can be recycled for multiple batch reactions. We used the knowledge gained from this study to produce several amines from carboxylic acid precursors using one‐pot biocatalytic reactions, several of which we report for the first time. These results expand our knowledge of these industrially relevant enzyme families to new substrates and contexts for environmentally friendly and potentially low‐cost synthesis of diverse aryl aldehydes and amines.

Biotechnology & Applied Microbiology↗
DOE OSTI2023

Preliminary Nuclear Containment Vessel Modeling for Multi-Hazard Probabilistic Risk Assessment under Seismic Hazards and Concrete Degradation

The current practice for natural phenomena hazards (NPH) risk assessment of nuclear facilities is to compute the risk for each hazard independently and then compound the total risk as a combination of single hazard risks. This state of practice does not consider correlations between hazards and the cascading impacts to structures, systems, and components (SSCs), and could thus underestimate the NPH risk or overestimate the nuclear facility safety. Events such as the Fukushima Daiichi accident have highlighted the importance of multi-hazard risk considerations to nuclear power plants (NPPs) that quantify the cascading damage effects to SSCs in the risk models. Moreover, the current fleet of NPPs in the United States is aging; these NPPs are now expected to operate well beyond their initially planned design life. Aging-related deterioration can potentially decrease the capacity of critical structures such as containment vessels to withstand NPH. Such aging considerations may not be adequately accounted for by the current NPH risk assessment guidelines. This paper presents a preliminary modeling and simulation of a representative reinforced concrete containment vessel subjected to seismic mainshock and aftershock considering concrete degradation due to alkali silica reaction. The broader aim is to develop multi-hazard time-dependent fragility functions that could be subsequently used in the probabilistic risk assessment (PRA) model. The multi-hazard component comes into play due to the consideration of damage to the containment vessel under seismic loads and concrete degradation. Consideration of concrete degradation also brings into play the time-dependent nature of the containment vessel response. The response of the containment vessel under varying degrees of concrete degradation to seismic loads is investigated. The results presented are simulated using the Multi-hazard Analysis for STOchastic time-DOmaiN phenomena (MASTODON) software for seismic analysis and the Blackbear software for concrete degradation and damage modeling. Both software are open source and developed within the Multiphysics Object-Oriented Simulation Environment (MOOSE).

42 ENGINEERING↗
DOE OSTI2021

Characterization of Surrogate Molten Salt Reactor Aerosol Streams

Measuring the aerosol evolution from MSRs is important for monitoring the off-gas system of the reactor and is particularly important for detecting off-normal conditions. In a molten salt reactor (MSR) accident scenario, an aerosol release would be a major factor in the source term. This aerosol stream would likely be generated from a breach in the cover gas system, which causes particles produced from fission itself to escape, or from a salt spill that produces aerosols through splashing and secondary reactions. The particle size of the produced aerosols is anticipated to vary greatly and range from 0.01 to 10 µm. The transport of these aerosols would be dependent on the particle size. A better understanding of aerosol generation, size, and monitoring methods are needed to inform estimation and mitigation of potential aerosolized source terms from MSRs. While salt spill experiments are being performed at Argonne National Laboratory, the development of aerosol characterization and monitoring methods are being developed at Oak Ridge National Laboratory. To generate prototypic aerosols for use in testing monitoring instruments and mitigation methods, a surrogate aerosol stream was produced with a Collison nebulizer, and the particle size distributions were measured with a cascade impactor. The results demonstrated that by changing the nebulizer pressure, the aerosol particle size distribution can be adjusted to best match the region of interest for experiments with higher pressures, driving the particle size down. However, nearly all aerosols formed exceeded 1 µm in diameter, providing a lower bound for the surrogate aerosol stream. In addition to verifying the applicability of this surrogate aerosol stream, this work has shown that a laser induced breakdown spectroscopy monitoring system that is under development is resilient to changes in particle sizes, increasing its robustness for off-gas monitoring.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2021

The Legionella Effector SdjA Is a Bifunctional Enzyme That Distinctly Regulates Phosphoribosyl Ubiquitination

Legionella pneumophila promotes its survival and replication in phagocytes by actively modulating cellular processes using effectors injected into host cells by its Dot/Icm type IV secretion system. Many of these effectors function to manipulate the ubiquitin network of infected cells, thus contributing to the biogenesis of the Legionella-containing vacuole (LCV), which is permissive for bacterial replication. Among these, members of the SidE effector family (SidEs) catalyze ubiquitination of functionally diverse host proteins by a mechanism that is chemically distinct from the canonical three-enzyme cascade. The activity of SidEs is regulated by two mechanisms: reversal of the phosphoribosyl ubiquitination by DupA and DupB and direct inactivation by SidJ, which is a calmodulin-dependent glutamylase. In many L. pneumophila strains, SidJ belongs to a two-member protein family. Its homolog SdjA appears to function differently from SidJ despite the high-level similarity in their primary sequences. Here, we found that SdjA is a bifunctional enzyme that exhibits distinct activities toward members of the SidE family. It inhibits the activity of SdeB and SdeC by glutamylation. Unexpectedly, it also functions as a deglutamylase that reverses SidJ-induced glutamylation on SdeA. Our results reveal that an enzyme can catalyze two completely opposite biochemical reactions, which highlights the distinct regulation of phosphoribosyl ubiquitination by the SidJ effector family.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Evolution of microstructures in radiation fields using a coupled binary-collision Monte Carlo phase field approach

The simulation of radiation effects in materials broadly falls into two categories. At short time and length scales lies the modeling of primary radiation damage, such as point defect creation, energy deposition, and ballistic mixing. This is followed by the modeling at longer time scales of thermally activated microstructure evolution and defect reactions, such as recombination, clustering, and coarsening. The binary collision Monte Carlo method is an established, numerically efficient method for the computation of primary radiation damage. Conversely, the phase field method is a state of the art method for microstructure evolution on longer time and length scales. Here we present a concurrent coupling of these two methods, overcoming the difference between the discrete object Monte Carlo paradigm for primary radiation damage and the continuum field variable approach for microstructure evolution. The coupling is bidirectional, in which the microstructure evolution in the MOOSE finite element frame- work provides the spatial scattering data set for the charged particle trans- port and receives point defect, mass transport, and heat source terms from the simulated collision cascades that contribute to the field variable evolution. The concurrent coupling scheme is implemented in the code Magpie and demonstrated by investigating patterning for a model irradiated immiscible binary alloy. The results from the coupled binary collision Monte Carlo/phase field simulations reproduce the results of analytical models for phase separation, phase mixing, and patterning, supporting the approach and indicating its utility for modeling real materials systems.

36 MATERIALS SCIENCE↗
DOE OSTI2026

The Relationship Between Catalyst and Solvent in Hydrogenation via Condensed Phase Heterogeneous Catalysis

To understand a system is to understand its components and their sum. Cascading interactions between catalyst, solvent, and reagent create a complex web of influences when heterogeneous catalysis meets the condensed phase. Due to the importance of heterogeneous catalysis in chemical manufacturing, and the present and growing potential of condensed phase chemistries, the understanding of these interactions is of paramount importance. To develop condensed phase heterogeneous catalysis, the field needs to develop understanding of the role of solvent in heterogeneous catalytic hydrogenation. While no small feat, fields such as biofuel and petroleum refining have established certain applicable generalities that can bridge the knowledge gap in emerging technologies such as integrated carbon capture and conversion to materials (IC 3 M). In this review, we thoughtfully probe the current paradigm of condensed phase catalysis by challenging the idea that catalyst and solvent are independent reaction design choices. Challenges such as lack of experimental stability studies and poor resolution on our conceptualization of the condensed phase environment are discussed. Parameters such as viscosity and the dielectric constant, and their role on reaction activity and stability are explored. Knowledge gained from established biomass and petroleum processes is discussed and used to anticipate behavior in novel processes.

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

Dimer Asymmetry and Light Activation Mechanism in Brucella Blue-Light Sensor Histidine Kinase

The ability to sense and respond to environmental cues is essential for adaptation and survival in living organisms. In bacteria, this process is accomplished by multidomain sensor histidine kinases that undergo autophosphorylation in response to specific stimuli, thereby triggering downstream signaling cascades. However, the molecular mechanism of allosteric activation is not fully understood in these important sensor proteins. Here, we report the full-length crystal structure of a blue light photoreceptor LOV histidine kinase (LOV-HK) involved in light-dependent virulence modulation in the pathogenic bacterium Brucella abortus. Joint analyses of dark and light structures determined in different signaling states have shown that LOV-HK transitions from a symmetric dark structure to a highly asymmetric light state. The initial local and subtle structural signal originated in the chromophore-binding LOV domain alters the dimer asymmetry via a coiled-coil rotary switch and helical bending in the helical spine. These amplified structural changes result in enhanced conformational flexibility and large-scale rearrangements that facilitate the phosphoryl transfer reaction in the HK domain.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

A Bi-Layer Dense/Porous Solid Electrolyte Interphase for Enhanced Lithium-Metal Stability

Due to its high theoretical capacity and low electrochemical potential, lithium metal is a highly investigated anode for next-generation high-energy batteries. However, the unstable chemical and topographical heterogeneous surface of lithium gives rise to safety and efficiency concerns that prevent it from being utilized in practical applications. Exposure to electrolyte leads to non-uniform, mixed organic-inorganic solid-electrolyte interphase (SEI) formation, starting a cascading to non-uniform flux distribution, consumption of active materials, and dendrite growth. The SEI is the key feature that will lead to harnessing the capabilities possible with lithium metal. In this work, the formation of a closed-host bi-layer solid electrolyte interphase (SEI) improves the stability of lithium anode. This is successfully realized by forming an interconnected porous LiF-rich artificial SEI in contact with Li metal, and a dense, stable in-situ formed upper layer SEI. The porous layer increases the number of Li/LiF interfaces, which reduces local volume fluctuations and improves Li+ diffusion along these interfaces. Additionally, the tortuous porous structure guides uniform Li+ flux distribution and mechanically suppresses dendrite propagation. The dense upper layer of the SEI accomplishes a closed-host design through reaction with LiNO3 additive and prevents continuous consumption of active materials seen without the additive included in the electrolyte. The duality of a dense top layer with porous bottom layer led to extended cycle life and improved rate performance, evidenced with symmetric cell testing, as well as full cell testing paired with sulfur and LiFePO4 (LFP) cathodes. This work is a good example of a rational design of the SEI, based on comprehensive consideration of various critical factors to improve Li-metal anode stability, and highlights a new pathway to improve cycling and rate performances of Li metal batteries.

25 ENERGY STORAGE↗
DOE OSTI2022

Role of carboxysomes in cyanobacterial CO 2 assimilation: CO 2 concentrating mechanisms and metabolon implications

Many carbon-fixing organisms have evolved CO 2 concentrating mechanisms (CCMs) to enhance the delivery of CO 2 to RuBisCO, while minimizing reactions with the competitive inhibitor, molecular O 2 . These distinct types of CCMs have been extensively studied using genetics, biochemistry, cell imaging, mass spectrometry, and metabolic flux analysis. Highlighted in this paper, the cyanobacterial CCM features a bacterial microcompartment (BMC) called ‘carboxysome’ in which RuBisCO is co-encapsulated with the enzyme carbonic anhydrase (CA) within a semi-permeable protein shell. Further, the cyanobacterial CCM is capable of increasing CO 2 around RuBisCO, leading to one of the most efficient processes known for fixing ambient CO 2 . The carboxysome life cycle is dynamic and creates a unique subcellular environment that promotes activity of the Calvin–Benson (CB) cycle. The carboxysome may function within a larger cellular metabolon, physical association of functionally coupled proteins, to enhance metabolite channelling and carbon flux. In light of CCMs, synthetic biology approaches have been used to improve enzyme complex for CO 2 fixations. Research on CCM-associated metabolons has also inspired biologists to engineer multi-step pathways by providing anchoring points for enzyme cascades to channel intermediate metabolites towards valuable products.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

Mechanisms and site requirements for NO and NH 3 oxidation on Cu/SSZ-13

Two series of Cu/SSZ-13 catalysts were synthesized via aqueous solution and solid-state ion exchange using SSZ-13 supports of varying Si/Al ratios. The isolated and multinuclear Cu content of these catalysts were determined by H 2 temperature programmed reduction (H 2 -TPR). Multinuclear Cu in these catalysts, including in situ Cu- dimers formed from ZCu II OH coupling and permanent CuO clusters, are active species for dry NO oxidation. NH 3 oxidation on these catalysts follows an internal SCR (i-SCR) mechanism, i.e., a portion of NH 3 is first oxidized to NO, then NO is selectively reduced by the remaining NH 3 to N 2 . NH 3 oxidation displays distinct kinetic behavior below ~300 °C and above ~400 °C. At low temperature the results indicate that NH 3 -solvated mobile Cu-ions are the active centers. CuO clusters, when present, also contribute to the low temperature activity by catalyzing NH 3 oxidation to NO. At high temperature, in situ Cu-dimers and CuO clusters catalyze NH 3 oxidation to NO, and isolated Cu-ions catalyze SCR to realize the cascade turnovers. For both NO and NH 3 oxidation, Cu-dimers balanced by framework charges of close proximity appear to be more active than Cu-dimers balanced by distant framework charges. However, the former Cu-dimers are less stable than the latter and tend to split into monomers in the presence of vicinal Brønsted acid sites. Via density functional theory (DFT) calculations, the i-SCR mechanism for low temperature NH 3 oxidation, i.e., the energetic favorability for the involvement of the NO intermediate, is justified. Furthermore, the DFT results also agree with experimental data that the formation of Cu-dimers from ZCu II OH dimerization is essential for NH 3 oxidation at high temperature.

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

Cryogenic Vibrationally Resolved Photoelectron Spectroscopy of OH–(H2O): Confirmation of Multidimensional Franck-Condon Simulation Results for the Transition State of the OH + H2O Reaction

We present a transition state spectroscopic study of the OH + H2O reaction using the experimental technique of cryogenic Negative Ion Photoelectron Spectroscopy (NIPES). The recorded NIPE spectrum at 193 nm exhibits multiple vibrational progressions that include excitations to the shared H atom antisymmetric stretching mode with an interval of 0.32 eV as well as other progressions, mainly involving the H bending and O…O symmetric stretching modes. The Vertical Detachment Energy (VDE) was measured at 3.53 eV, whereas an upper limit for the Adiabatic Detachment Energy (ADE) was estimated at 2.90 eV. These values are in excellent agreement with the theoretically computed values of 3.51 eV and 2.83 eV respectively, obtained at the CCSD(T)/aug-cc-pV5Z level of theory. The recorded NIPE spectrum is in very good agreement when compared to the one recently reported from four-dimensional Franck-Condon simulations, in which a similar spectral profile was predicted. Besides observing the ground state, a charge-transfer excited state in the form of [OH–(H2O)+] is identified with a relative energy of 1.39 eV, well matching the previous prediction of 1.36 eV. This work was supported by U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, and performed using EMSL, a national scientific user facility sponsored by DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory, which is operated by Battelle Memorial Institute for the DOE. The theoretical calculations were conducted on EMSL’s “Cascade” Supercomputer. This research also used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

Cao, Wenjin↗