Polyrate is a suite of computer programs for the calculation of chemical reaction rates of polyatomic species (including atoms and diatoms as special cases) by variational transition state theory (VTST); conventional transition state theory is also supported. Polyrate can calculate the rate constants for both bimolecular reactions and unimolecular reactions, and it can be applied to reactions in the gas phase, liquid solution phase, or solid state and to reactions at gas-solid interfaces. Polyrate can perform VTST calculations on gas-phase reactions with both tight and loose transition states. For tight transition states it uses the reaction-path (RP) variational transition state theory developed by Garrett and Truhlar, and for loose transition states it uses variable-reaction-coordinate (VRC) variational transition state theory developed by Georgievskii and Klippenstein. The RP methods used for tight transition states are conventional transition state theory, canonical variational transition state theory (CVT), and microcanonical variational transition state theory (mu VT) with multidimensional semiclassical approximations for tunneling and nonclassical reflection. For VRC calculations, rate constants may be calculated for canonical or microcanonical ensembles or energy-and total-angular-momentum resolved microcanonical ensembles. Pressure-dependent rate constants for elementary reactions can be computed using system-specific quantum RRK theory (SS-QRRK) with the information obtained from high-pressure limit VTST calculation as input by using the SS-QRRK utility code. Alternatively, Polyrate 2023 may be interfaced with TUMME 2023 for a master-equation treatment of pressure dependence or to obtain phenomenological rate constants for complex mechanisms. Potential energy surfaces may be analytic functions evaluated by subroutines, or they may be implicit surfaces defined by electronic structure input files or interface subroutines containing energies, gradients, and force constants (Hessians). For the latter, Polyrate can be used in conjunction with various interfaces to electronic structure programs for direct dynamics, and it has routines designed to make such interfacing straightforward. Polyrate supports six options for direct dynamics, namely (i) straight single-level direct dynamics, (ii) zero-order interpolated variational transition state theory (IVTST-0), (iii) first-order interpolated variational transition state theory (IVTST-1), (iv) interpolated variational transition state theory by mapping (IVTST-M), (v) variational transition state theory with interpolated single-point energies (VTST-ISPE), and (vi) variational transition state theory with interpolated optimized corrections (VTST-IOC). Polyrate can handle multistructural and torsional-potential anharmonicity in conjunction with the MSTor program. Polyrate 2023 contains 112 test runs, and 46 of these are for direct dynamics calculations; 85 of the test runs are single-level runs, and 27 are dual-level calculations.

done Most notable is the conversion of methane to methyl bisulfate in the presence of a platinum catalyst. The reaction is carried out in 100% sulfuric acid using SO 3 as et al. 1998). In similar work, methane undergoes direct partial oxidation using iodate salts with catalytic amounts of chloride in protic solvents. In HTFA (where TFA is trifluoroacetate), greater than 20% methane conversion with more than 85% selectivity for MeTFA were achieved (Fortman et al. 2014). Work is continuing for closing trapped in the cross channels of the pores. The currently accepted mechanism is referred to as the hydrocarbon pool (HCP) mechanism. If not supplied with sufficient additional methanol (or DME), the HMB eventually leads to coke formation. At reaction temperatures below 250 °C, no methanol conversion is observed. Only methanol and dimethyl ether appear in the effluents. There is a fast deactivation of the catalyst at lower temperatures with the appearance of light olefins and other hydrocarbons in the temperature of 300−325 °C. The yield of hydrocarbon products catalytically to produce drop-in and and methoxymethyl-furfural) that can then upgraded precursors converted into distillate-range hydrocarbons through hydrogenation, condensation, and hydrodeoxygenation. ) acids can converted through converted hydrocarbon fuel ketonization, aldol condensation, and oxides of the spinel or perovskite structure, such as Co 3 O 4 that exhibit overpotentials of ~350 mV at a current density of 10 mA/cm 2 in 1.0 M KOH, have shown the most success (Esswein et al. 2009). A Ni foam ionomer-impregnated Ni-Fe cathode, which exhibited ~0.35 V overpotential at 400 mA/cm 2 in 1.0 M KOH solution at 40 °C, displayed even better OER performance (Xiao et al. 2012). Other catalysts, such as the recently developed ultrathin Ni-Fe layered double hydroxide (NiFe-LDH) nanoplates on mildly oxidized multiwalled CNTs (Gong et al. 2013), are difficult to compare directly to AEM electrolyzers, since the catalyst loading, catalyst morphology, interaction between catalyst and AEM ionomer, and mass transport challenges in ionomer-impregnated anodes are not present in model systems (Shen

Nuclear power today accounts for approximately 20% of the electrical supply for the US. It provides reliable energy that helps to stabilize the national grid. In contrast to current nuclear power facilities, future concepts operate at higher temperatures, are operationally more efficient, more fully utilize the energy stored within the fuel, and reduce the amount of waste produced. Recent advances in chemistry and materials sciences provide an unprecedented opportunity to develop the critical systems—the fuel, coolant, and structural materials—needed for deployment of advanced nuclear reactor designs. To address the challenge of stringent demands on material systems as their properties and performance continuously evolve over the operational lifetime, the frameworks to uncover the underlying processes that cause reduced performance have been developed over the last decade. There is now the prospect of designing materials that report upon their own damage, are self-healing, and leverage what would be considered deleterious chemical processes to increase their performance within advanced reactor designs. Success will provide an energy source needed to secure a stable and safe energy supply for the nation. To identify the key research directions required to discover the chemical processes and material degradation mechanisms that result in loss of performance of the fuel, coolant, and structural materials, nearly 150 theoreticians, computational experts, and experimentalists from industry, national laboratories, academia, and federal agencies participated in a workshop held in August 2017. Based on the discussions held at the workshop, five Priority Research Directions (PRDs) were identified. These PRDs defined the key scientific challenges that must be met as well as the opportunities that can be exploited to achieve a multi-scale spatial and temporal understanding of fundamental processes that govern the properties and performance of the different material systems required for advanced reactors.

Energy technologies affect virtually every aspect of life in modern societies—including transportation, utilities, agriculture, medicine, and the availability of a myriad of consumer products—and depend on human ability to accelerate and to guide chemical transformations. Controlling these transformations, which occur in the microscopic world of atoms and molecules, forms the basis of countless technologies such as production of fuels, fertilizers, plastics, pharmaceuticals and much more. At the very core of these chemical transformations are catalysts—specialized and often highly complex types of matter that allow chemical reactions to occur rapidly and produce specific products. Catalysts also have the remarkable ability to perform their tasks millions of times without themselves being consumed. The discovery of inexpensive and widely-deployable energy and chemical technologies, and their underpinning catalysis science, is critical to ensure the economic viability of US energy and chemical industries. Over the past decade, remarkable new tools have been discovered that allow the observation of catalytic transformations in exquisite detail, and assembly of novel and elaborate catalytic architectures with atomic precision. Furthermore, increasingly sophisticated theoretical and computational tools allow understanding of the essential details of the catalytic processes, and this overall progress has led to the discovery of catalysts with superior performance more»

Cover artwork: Experiments using specially shaped pulses of light demonstrate that quantum states can be guided along “superadiabatic” trajectories, allowing for coherent manipulations with both high speed and robustness. This section discusses computational approaches that merge quantum and classical pieces by passing information back and forth in real time, with applications to complex molecules and materials and to “open” quantum systems in which quantum orbitals interact with an effectively classical environment, such as a liquid. Applications of interest to BES include the development of complex, bio-inspired molecules with the potential for creating chemical energy from light (artificial photosynthesis) and the creation of new quantum materials, ranging from improving the understanding of defects that limit the scaling of current computers to ever smaller sizes, to new families of magnets and high-temperature superconductors.

Computers have revolutionized every aspect of our lives. Yet in science, the most tantalizing applications of computing lie just beyond our reach. The current quest to build an exascale computer with one thousand times the capability of today’s fastest machines (and more than a million times that of a laptop) will take researchers over the next horizon. The field of materials, chemical reactions, and compounds is inherently complex. Imagine millions of new materials with new functionalities waiting to be discovered—while researchers also seek to extend those materials that are known to a dizzying number of new forms. We could translate massive amounts of data from high precision experiments into new understanding through data mining and analysis. We could have at our disposal the ability to predict the properties of these materials, to follow their transformations during reactions on an atom-by-atom basis, and to discover completely new chemical pathways or physical states of matter. Extending these predictions from the nanoscale to the mesoscale, from the ultrafast world of reactions to long-time simulations to predict the lifetime performance of materials, and to the discovery of new materials and processes will have a profound impact on energy technology. In addition, discovery more»

Advances in science and technology over the past century have been driven by an improved understanding of matter on ultrashort length scales, reaching down to atomic dimensions. In contrast, methods aimed at understanding dynamics on the ultrafast time scales of atomic motion are comparatively new. Ultrafast characterization has already yielded crucial insights not attainable from slower measurements. The interplay between atomic-scale structure and the associated ultrafast dynamics governs the macroscopic functionality observed in matter. Understanding and controlling materials and chemical processes at these length and time scales are key to discovery and innovation to advance energy and related national priorities. The recent availability of x-ray free-electron lasers (XFELs) provides a probe that simultaneously reaches the required resolution in both space and time. X-ray wavelengths extend down to the atomic scale, while x-ray pulse durations now lie in the femtosecond (10-15 seconds) range. This capability allows the evolution of materials and chemical processes to be followed on their natural time and length scales, providing fundamental scientific understanding of the complexity of the world around us. Because of the transformative potential of new ultrafast x-ray characterization tools provided by XFELs, it is imperative to lay out a roadmap for the exciting scientific opportunities that can be explored using these research tools. To identify the highest priority research opportunities, the U.S. Department of Energy Office of Basic Energy Sciences (BES) convened a roundtable of experts in chemistry, materials physics, and ultrafast and x-ray science. This group of experimentalists and theorists met on October 25–26, 2017 to explore research opportunities that will leverage current and imminent ultrafast XFEL capabilities and advance the broader BES science mission. This report summarizes major new scientific frontiers that can be addressed by emerging XFEL capabilities. The conclusions of the roundtable discussion are summarized in the following three Priority Research Opportunities (PROs).

Computers have revolutionized every aspect of our lives. Yet in science, the most tantalizing applications of computing lie just beyond our reach. The current quest to build an exascale computer with one thousand times the capability of today’s fastest machines (and more than a million times that of a laptop) will take researchers over the next horizon. The field of materials, chemical reactions, and compounds is inherently complex. Imagine millions of new materials with new functionalities waiting to be discovered — while researchers also seek to extend those materials that are known to a dizzying number of new forms. We could translate massive amounts of data from high precision experiments into new understanding through data mining and analysis. We could have at our disposal the ability to predict the properties of these materials, to follow their transformations during reactions on an atom-by-atom basis, and to discover completely new chemical pathways or physical states of matter. Extending these predictions from the nanoscale to the mesoscale, from the ultrafast world of reactions to long-time simulations to predict the lifetime performance of materials, and to the discovery of new materials and processes will have a profound impact on energy technology. In addition, discovery of new materials is vital to move computing beyond Moore’s law. To realize this vision, more than hardware is needed. New algorithms to take advantage of the increase in computing power, new programming paradigms, and new ways of mining massive data sets are needed as well. This report summarizes the opportunities and the requisite computing ecosystem needed to realize the potential before us. In addition to pursuing new and more complete physical models and theoretical frameworks, this review found that the following broadly grouped areas relevant to the U.S. Department of Energy (DOE) Office of Advanced Scientific Computing Research (ASCR) would directly affect the Basic Energy Sciences (BES) mission need. Simulation, visualization, and data analysis are crucial for advances in energy science and technology. Revolutionary mathematical, software, and algorithm developments are required in all areas of BES science to take advantage of exascale computing architectures and to meet data analysis, management, and workflow needs. In partnership with ASCR, BES has an emerging and pressing need to develop new and disruptive capabilities in data science. More capable and larger high-performance computing (HPC) and data ecosystems are required to support priority research in BES. Continued success in BES research requires developing the next-generation workforce through education and training and by providing sustained career opportunities.

For decades, scientists have predicted that devices based on “quantum phenomena” will be able to store and manipulate information to provide radical new approaches for computing, communication, and sensing. However, only recently have quantum phenomena been incorporated into technologies for next-generation computers, sensors, and detectors that demonstrate performance characteristics rivaling those of their conventional counterparts. These devices clearly demonstrate the enormous potential for future quantum-based technologies. The novel quantum device capabilities currently envisioned include enhanced resolution in imaging, sensors, and detectors; advanced cryptography for more secure communication; and significantly larger computational capabilities at speeds far greater than those possible in classical computing. However, realizing these advances requires a detailed understanding of how quantum systems (including quantum materials or assemblies of trapped ions and electrons) behave, accurate knowledge of how to integrate the components into complex systems, and precise control of the structures. In this context, creating and controlling quantum states within molecules and materials offer exciting scientific opportunities for fundamental research, as well as for enabling next-generation quantum-based technologies. Numerous questions remain, ranging from how quantum interactions may enable innovation through the creation of novel quantum systems, to how these new quantum technologies can advance our understanding of matter and chemistry at the most fundamental levels. To address these questions and identify priority research opportunities (PROs), the US Department of Energy (DOE) Office of Basic Energy Sciences (BES) convened a roundtable of experts in quantum materials and quantum systems encompassing the fields of physics, chemistry, materials synthesis science, device engineering, detector technology, and atomic-scale characterization techniques. This group of experimentalists and theorists met on October 30–31, 2017, to explore scientific research opportunities in this rapidly moving field, in which BES support can play a key role in advancing and utilizing quantum information science (QIS). The goals of this roundtable were to define the unique roles for BES in this active research field and to provide input on future research directions, forming the basis for a coordinated, long-term research effort that will enable major advances in quantum-based science and technology. BES is uniquely positioned to advance this field because of its long history of fundamental research support for both materials and chemical sciences, along with its construction and operation of world-class scientific user facilities. Fundamental research in this area is strongly coupled to DOE efforts in scientific computing, high-energy physics, and accelerator/detector research and related to activities in “Beyond Moore’s Law” computing, next-generation semiconductor materials, and exascale computing.

Energy technologies affect virtually every aspect of life in modern societies—including transportation, utilities, agriculture, medicine, and the availability of a myriad of consumer products—and depend on human ability to accelerate and to guide chemical transformations. Controlling these transformations, which occur in the microscopic world of atoms and molecules, forms the basis of countless technologies such as production of fuels, fertilizers, plastics, pharmaceuticals and much more. At the very core of these chemical transformations are catalysts—specialized and often highly complex types of matter that allow chemical reactions to occur rapidly and produce specific products. Catalysts also have the remarkable ability to perform their tasks millions of times without themselves being consumed. The discovery of inexpensive and widely-deployable energy and chemical technologies, and their underpinning catalysis science, is critical to ensure the economic viability of U.S. energy and chemical industries. Over the past decade, remarkable new tools have been discovered that allow the observation of catalytic transformations in exquisite detail, and assembly of novel and elaborate catalytic architectures with atomic precision. Furthermore, increasingly sophisticated theoretical and computational tools allow understanding of the essential details of the catalytic processes, and this overall progress has led to the discovery of catalysts with superior performance and the associated economic benefit. In the next decade and beyond, science promises to revolutionize how catalysts and catalytic processes are designed, to enable the introduction of new energy resources, to provide routes to sustainable synthesis of chemicals and other valuable materials, and to create novel approaches to chemical energy storage. This report is the result of the Basic Energy Sciences Workshop on Basic Research Needs for Catalysis Science to Transform Energy Technologies that was held in May 2017, and was attended by more than 100 leading national and international scientific experts. The attendees were organized into four panels: 1. Diversified Energy Feedstocks and Carriers, 2. Novel Approaches to Energy Transformations, 3. Advanced Chemical Conversion Approaches, and 4. Crosscutting Capabilities and Challenges: Synthesis, Theory, and Characterization. The workshop identified five priority research directions (PRDs) that are aimed at harnessing complexity in catalysis to create next-generation energy technologies and realizing efficient catalytic processes to increase the diversity of resources for production of chemicals and energy.

The last decade has opened rich new horizons in electrical energy storage, with compelling impacts on society. Personal electronics have transformed from a novelty to a necessity. New options for transportation are burgeoning. In energy storage science, emerging new approaches are illuminating the inner workings of energy storage at the atomic and molecular scales with extensions to the meso and macro levels. The stage is set — with ripe new directions for basic energy storage science and promising new opportunities for energy storage for the electricity grid, transportation, the internet of things, and national defense. Next generation electrical energy storage could be as transformational for energy applications as lithium-ion batteries were for personal electronics. This report examines the opportunities in basic energy storage science that will bring this vision for the future to fruition. Sea changes are in the offing, moving from intuitive speculation to confirmed scientific knowledge, from trial-and-error serendipity to science-based design, and from qualitative models to quantitative predictions. To navigate towards these changes, Priority Research Directions (PRDs) were formulated by 175 leading scientists and engineers during a Basic Research Needs Workshop on Next Generation Electrical Energy Storage held in Gaithersburg, Maryland, on March 27-29, 2017. This diverse community included experts in theory, simulation, characterization, electrochemistry, and synthesis of electrochemically active materials and chemistries. They uncovered a rich horizon of compelling directions that promise to link diverse electrochemical phenomena (such as solvation, mobility, reactivity, and degradation) in a single interactive framework.

ADVERTISEMENT RETURN TO ISSUEPREVSpecial Issue Prefac...Special Issue PrefaceNEXTAutobiography of Bruce C. GarrettBruce C. GarrettCite this: J. Phys. Chem. B 2016, 120, 8, 1393–1394Publication Date (Web):March 3, 2016Publication History Published online3 March 2016Published inissue 3 March 2016https://pubs.acs.org/doi/10.1021/acs.jpcb.5b09514https://doi.org/10.1021/acs.jpcb.5b09514introductionACS PublicationsCopyright © 2016 American Chemical Society. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views410Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (116 KB) Get e-AlertscloseSUBJECTS:Luminescence,Nucleation,Reaction rate theory,Students Get e-Alerts

Hans-Joachim Freund opened the discussion of the paper by Alberto Roldan: How is the atomic hydrogen produced on the greigite surface? In the paper (DOI: 10.1039/C5FD00186B) there is no comment whether you studied dissociate hydrogen adsorption. Alberto Roldan answered: We agree

The scientific discoveries that expand the frontiers of human understanding, and that lead to the innovations of our technological world, require scientific tools and instrumentation to enable observation and manipulation of the physical world. As science advances, so too must its tools; the quest for deeper scientific insights and the drive to control chemistry and materials at the atomic and molecular levels require increasingly powerful and sophisticated instruments. A secure energy future requires technologies that use existing resources more efficiently, harness renewable resources, and efficiently store energy. The urgent demand for new energy technologies has ushered in a new era in scientific pursuit to decipher the complexity found at the core of chemical and materials processes, as articulated by the basic energy science research community in its series of Basic Research Needs (BRN) workshops. Historically, novel experimental tools and methods have been foundational in both scientific and technological advances — ranging from high-resolution microscopes that “see” atomic structures, to lithography that has enabled advances in semiconductors and computing. Today, expanding the frontiers of basic research requires new generations of instrumentation to reveal the intricacies of complex materials and chemical systems; energy systems in realistic working environments; and systems that are dynamical, far from equilibrium, and extremely heterogeneous. A concerted effort to invent, design, and build scientific instrumentation will enable new scientific breakthroughs and transformative technologies to address the most pressing energy challenges of the 21st century. To identify the highest priorities for the instrumentation innovation and development needed to address grand challenges in energy sciences, the U.S. Department of Energy’s Office of Basic Energy Sciences sponsored a workshop entitled, “Basic Research Needs for Innovation and Discovery of Transformative Experimental Tools” on June 1–3, 2016 near Washington, D.C. The workshop was attended by approximately 100 leading national and international scientific experts representing areas of basic energy sciences in chemistry, materials, physics, and biology, and included a mix of experimentalists and theorists.

Philip Davies opened the discussion of the introductory lecture by Avelino Corma: The metal nanoparticles inside the zeolites are in a different environment from those outside. Is there any difference in their chemistry and their catalytic behaviour? Avelino Corma answered: We we

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Isotopic substitution of muonium for hydrogen provides an unparalleled opportunity to deepen our understanding of quantum mass effects on chemical reactions. A recent topical review in this journal of the thermal and vibrationally state-selected reaction of Mu with H-2 raises a number of issues that are addressed here. We show that some earlier quantum mechanical calculations of the Mu + H-2 reaction, which are highlighted in this review, and which have been used to benchmark approximate methods, are in error by as much as 19% in the low-temperature limit. We demonstrate that an approximate treatment of the Born-Oppenheimer diagonal correction that was used in some recent studies is not valid for treating the vibrationally state-selected reaction. We also discuss why vibrationally adiabatic potentials that neglect bend zero-point energy are not a useful analytical tool for understanding reaction rates, and why vibrationally non-adiabatic transitions cannot be understood by considering tunnelling through vibrationally adiabatic potentials. Finally, we present calculations on a hierarchical family of potential energy surfaces to assess the sensitivity of rate constants to the quality of the potential surface.

, 445 (2011); 331 Science et al. S. Venkataramani Temperature Magnetic Bistability of Molecules in Homogeneous Solution at Room This copy is for your personal, non-commercial use only. clicking here. colleagues, clients, or customers by , you can order high-quality copies for your If you wish to distribute this article to others here. following the guidelines can be obtained by Permission to republish or repurpose articles or portions of articles ): December 4, 2013 www.sciencemag.org (this information is current as of The following resources related to this article are available online at http://www.sciencemag.org/content/331/6016/445.full.html version of this article at: including high-resolution figures, can be found in the online Updated information and services, http://www.sciencemag.org/content/suppl/2011/01/25/331.6016.445.DC1.html can be found at: Supporting Online Material http://www.sciencemag.org/cgi/collection/chemistry Chemistry subject collections: This article appears in the following

We report a new advance in the study of muonium (Mu) reactivity; specifically, we report the rate constant for the Mu + H-2(vibrational quantum number n = 1) reaction determined by measurements at 300 K and by converged quantum mechanical calculations. Comparisons are made with earlier results for D + H-2 (n = 1) and with the corresponding thermal reaction rates. The measurements are a sensitive probe of the high-curvature region in the entrance valley of the potential energy surface (PES) and thus provide a qualitatively different probe of the PES than that provided by any previous experiment.