Article
Chemistry, Physical
Eugene Mamontov, Yongqiang Cheng, Luke L. Daemen, Alexander I. Kolesnikov, Anibal J. Ramirez-Cuesta, Matthew R. Ryder, Matthew B. Stone
Summary: A recent screening study identified apilimod as effective against SARS-CoV-2 virus and tetrandrine showed synergy with remdesivir. The rotational dynamics of methyl groups in apilimod and tetrandrine are faster than in remdesivir due to reduced energy barriers, which may impact their bioactivity. Screening studies based on computed potential energy profiles can help identify promising drug candidates within a drug class.
CHEMICAL PHYSICS LETTERS
(2021)
Article
Biochemistry & Molecular Biology
Madina Zh. Sadvakassova, Andrei I. I. Khlebnikov, Abdigali A. A. Bakibaev, Oleg A. A. Kotelnikov, Rakhmetulla Sh. Erkassov, Madeniyet A. A. Yelubay, Manar A. A. Issabayeva
Summary: N-Benzhydrylformamides are pharmacologically active compounds with various biological activities. The conformation of these compounds is influenced by the presence of substituents, particularly at the nitrogen atom and in the ortho-positions of the diphenylmethane moiety. Through NMR and DFT calculations, the rotational barriers of the formyl and aryl fragments in N-benzhydrylformamides were investigated. The results showed that the DFT method satisfactorily reproduced the experimental rotational barrier of the formyl group, while ortho-substituents significantly hindered the rotation of the aryl fragment.
Article
Engineering, Environmental
Yujie Lv, Yifan Jing, Bao Zhang, Yingxue Li, Guanglin Xia, Xuebin Yu, Pengru Huang, Haixiang Huang, Bogu Liu, Jianguang Yuan, Ying Wu
Summary: This study investigates the introduction of MXenes as catalysts into Mg(BH4)2 to improve its hydrogen storage properties. The addition of 30 wt% MXenes significantly lowers the dehydrogenation temperature of Mg(BH4)2 and enhances its dehydrogenation rate and capacity. Theoretical calculations and experimental analysis reveal the important role of electron transfer and dehybridization effects at the Mg(BH4)2/MXenes interfaces in improving the dehydrogenation properties.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Qinfu Zhao, Jianpeng Guo, Mengyu Su, Bingbing Suo, Haiyan Zhu, Bo Zhou, Zhiyong Zhang, Qi Song
Summary: This study considers the influence of attempt frequency on ionic conductivity, calculates the attempt frequencies of carrier migrations in Na3OBH4 and Na3OBr using density functional theory, and investigates the effect of substituting Br- with the [BH4](-) anion on the conductivity of sodium cations.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Katsuhiko Nishimura, Kosuke Imai, Kenji Matsuda, Norio Nunomura, Taiki Tsuchiya, Yosikazu Isikawa, Hiroki Adachi, Wayne D. Hutchison
Summary: The magnetization of binary Al-Mg alloys and intermetallic compounds exhibit different properties, such as paramagnetism and diamagnetism, at different temperatures. Additionally, the study found that the electronic specific heat coefficients of aluminum and magnesium are almost the same.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Ceramics
Mariia S. Koroleva, Aleksei G. Krasnov, Denis A. Osinkin, Dina G. Kellerman, Andrey S. Stoporev, Irina V. Piir
Summary: This work investigates the structure and properties of synthesized Bi1.6Mg0.8-xCuxNb1.6O7-delta semiconductors and their Li-doped compositions. The preferential location of Cu and Li atoms at certain sites and Mg atoms at others is revealed through various diffraction methods and calculations. The materials exhibit weak antiferromagnetic exchange interactions, high mixed electronic-ionic conductivity, and compatibility with other compounds, suggesting their potential use in composite electrodes for enhanced oxygen conductivity.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Javier Catalan, Ana Martin-Somer, Henning Hopf
Summary: In this study, we provide experimental and theoretical evidence that the all-trans ttbP4 can undergo a conformational change in a molecular environment as restricted as the crystalline phase when it is electronically excited. This finding helps to clarify the viability of the torsional mechanism in the vision mechanism of bacteriorhodopsin. Additionally, we show that the fluorescence emission of ttbP4 in the crystalline phase is the combination of two bands corresponding to the emission from two different ttbP4 conformers.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2023)
Article
Chemistry, Physical
Michael Wiesinger, Christian Knupfer, Holger Elsen, Jonathan Mai, Jens Langer, Sjoerd Harder
Summary: The reaction of a MgN(2)/BaN(2) mixture with PhSiH3 produced three unique heterometallic Mg/Ba hydride clusters, with product formation controlled by the Mg/Ba ratio and temperature. Catalytic hydrogenation experiments showed that MgN(2) is only active in imine hydrogenation, while the presence of Ba is necessary for alkene and alkyne hydrogenation.
Article
Chemistry, Physical
Bruna Nadia N. Silva, Heloise O. Pastore, Alexandre A. Leitao
Summary: This study examines the simulated structures of K-, Mg-, and Ca-magadiites based on Namagadiite. The results show that Na- and K-magadiites have longer coordinated bond lengths and higher basal spacing values, while solids containing divalent cations form the strongest hydrogen bonds between water molecules and layers. Vibrational analysis identifies different stretching and bending motions of water molecules, and simulated-experimental comparison suggests a sequential adsorption of water molecules in dehydrated samples. Thermodynamic analysis confirms the difficulty of achieving complete sodium-potassium exchange, except for Ca-magadiite which can form spontaneously.
APPLIED CLAY SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Kui Xia, Xianguang Zeng, Huafeng Zhu, Jing Gong, Hong Luo
Summary: Mg-doped Li2ZnTi3O8/C samples were prepared by sol-gel method and microwave tube sintering furnace. The presence of Mg2+ doping was confirmed by XRD, TEM, and XPS spectroscopy. The doping of Mg2+ improved the ionic and electronic conductivity of Li2ZnTi3O8/C, reducing polarization and exhibiting excellent cycling and rate performance.
Article
Chemistry, Physical
Zhipeng Li, Weixin Huang, Jiaxing Liu, Kangle Lv, Qin Li
Summary: The study successfully constructed a ternary CdS@Au/MXene composite with MXene as a support, achieving a high H-2 production rate. The enhancement was predominantly attributed to the dual Schottky barriers formed at the interface of CdS@Au/MXene.
Article
Chemistry, Multidisciplinary
Iurii Dovgaliuk, Irena Senkovska, Xiao Li, Vadim Dyadkin, Yaroslav Filinchuk, Dmitry Chernyshov
Summary: Using in situ powder X-ray diffraction, this study evaluated the intracrystalline diffusion scenarios of Ar, Kr, and Xe adsorption by nanoporous gamma-Mg(BH4)(2). Different noble gas molecules exhibit varying diffusion pathways within the crystal structure, influenced by their kinetic diameter and temperature. The results indicate that smaller Ar atoms diffuse equally through both intra- and interchannel apertures, while medium sized Kr molecules show contributions from two parallel transport mechanisms and larger Xe atoms primarily diffuse along 1D channels with the highest barrier.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Physics, Condensed Matter
Artur P. Durajski, Grzegorz T. Kasprzak
Summary: The efficacy of bilayer BC7 as an anode material for Li/Na/Mg-ion batteries is examined using the first-principles calculation method. The results demonstrate a strong swelling effect caused by the penetration of Na and Mg atoms into the interlayer space of BC7, rendering BC7 anodes unsuitable for Na and Mg-ion batteries. On the other hand, intercalation of Li into the BC7 structure can deliver an acceptable volume expansion of the 2D anode and a theoretical capacity of 423.69 mAh/g, higher than that of commonly used anodes for Li-ion batteries.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Materials Science, Multidisciplinary
Grzegorz T. Kasprzak, Radoslaw Szczesniak, Artur P. Durajski
Summary: In this study, the possibility of using 2D material NC7 as an anode material for Li/Na/Mg-ion battery was explored through first-principles calculations. The results show that pristine bilayer NC7 is dynamically and thermally stable, but the volume expansion after Na- and Mg-intercalation eliminates it as a candidate for Na- and Mg-ion battery anode. However, Li-intercalated NC7 bilayer exhibits a small swelling effect, thermal stability, high theoretical capacity, low open circuit voltage, and diffusion barriers, making it a highly promising alternative material for Li-ion battery anode with great structural sturdiness.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Biochemistry & Molecular Biology
Kiyoshi Fujisawa, Syuhei Sakuma, Riko Ikarugi, Anex Jose, Edward I. Solomon
Summary: Mono nuclear manganese(III) peroxido complexes were structurally characterized, with characteristic ν(O-O) and ν(Mn-O) stretchings determined using (H2O2)-O-18 for the first time. The decomposed products were obtained, providing further insight into their structural parameters. This study offers important information for understanding the reaction intermediates in manganese containing proteins.
JOURNAL OF INORGANIC BIOCHEMISTRY
(2021)
Article
Chemistry, Physical
Thantip Roongcharoen, Xin Yang, Shuang Han, Luca Sementa, Tejs Vegge, Heine Anton Hansen, Alessandro Fortunelli
Summary: In this study, we computationally investigate the energetics and mechanisms of oxidation of Pt-Mn systems. Our findings demonstrate that Mn has a strong tendency to alloy with Pt, and surface Mn atoms can dissociate O2 and form MnOx surface oxide structures. These surface oxide structures are supported on a metallic framework and create vacancy sites. The vacancies promote the oxidation process and the energy barriers for oxidation steps are typically around 0.9-1.0 eV.
FARADAY DISCUSSIONS
(2023)
Article
Chemistry, Multidisciplinary
Xueping Qin, Tejs Vegge, Heine Anton Hansen
Summary: Electrochemical CO2 reduction reaction (CO2RR) is a promising technology for clean energy economy. This study investigates the mechanism of CO2RR using ab initio molecular dynamics simulations. The results show that the presence of K cations promotes CO2 activation and inhibits the competitive hydrogen evolution reaction (HER) at the inner-sphere interface. A comprehensive free energy diagram of CO2RR and HER is derived, demonstrating the critical role of cations in facilitating CO2 adsorption while suppressing hydrogen evolution.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Pernille D. Pedersen, Tejs Vegge, Thomas Bligaard, Heine A. Hansen
Summary: Two-dimensional transition metal dichalcogenides show promise as catalysts for CO2 reduction, with potential to produce products beyond CO. The stability and adsorption properties of different materials play a significant role in CO2 reduction. Transition metal ditellurides are identified as a promising class of materials.
Article
Chemistry, Physical
Ediga Umeshbabu, Satyanarayana Maddukuri, Doron Aurbach, Maximilian Fichtner, Anji Reddy Munnangi
Summary: We introduced a garnet-type lithium metal fluoride, Li3Na3M2F12 (M = Al, Sc, In), as solid-state lithium-ion conductors for the first time. The mechanically milled Li3Na3M2F12 compounds crystallized in a cubic garnet-like structure. The ionic conductivities of Li3Na3Al2F12, Li3Na3Sc2F12, and Li3Na3In2F12 are relatively low, but still better than the oxide analogues Li(3)Ln(3)Te(2)O(12) (Ln = Er, Gd, Tb, Nd). Strategies for further improving conductivities of garnet-type Li3Na3M2F12 were also presented.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Electrochemistry
Benjamin H. H. Sjolin, Peter B. B. Jorgensen, Andrea Fedrigucci, Tejs Vegge, Arghya Bhowmik, Ivano E. E. Castelli
Summary: We developed a multi-target multi-fidelity workflow to search for stable high-performance solid state electrolytes for all-solid state batteries. The workflow utilizes thermodynamic and kinetic properties calculations, including phase and electrochemical stability, semiconducting behavior, and ionic diffusivity. By using a surrogate model to predict the transition state structure, the calculation of kinetic properties is greatly accelerated without significant loss of accuracy.
BATTERIES & SUPERCAPS
(2023)
Article
Electrochemistry
Janina Drews, Johannes Wiedemann, Rudi Ruben Maca Alaluf, Liping Wang, J. Alberto Blazquez, Zhirong Zhao-Karger, Maximilian Fichtner, Timo Danner, Arnulf Latz
Summary: The impact of different mass loadings and particle size distribution of the active material on the performance of magnesium-ion batteries has been studied. A detailed continuum model is developed to describe the complex intercalation process of magnesium into a Chevrel phase cathode, taking into account the thermodynamics, kinetics, and the influence of desolvation on electrochemical reactions.
BATTERIES & SUPERCAPS
(2023)
Article
Instruments & Instrumentation
L. o. Sandberg, M. L. Haubro, K. M. L. Krighaar, R. Edberg, I. M. B. Fjellvag, M. Guthrie, A. T. Holmes, L. Mangin-Thro, A. Wildes, P. Henelius, K. Lefmann, P. P. Deen
Summary: This paper provides an overview of a pressure cell designed for the study of strongly correlated magnetic systems and quantum magnets using neutron scattering techniques. The pressure cell is capable of accommodating single crystals and applying high pressure at cryogenic temperatures. It is consistent with the requirements of inelastic neutron scattering and neutron polarization analysis. The pressure cell has a highly uniform and low background for a wide scattering angle.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Chemistry, Physical
Shuang Han, Steen Lysgaard, Tejs Vegge, Heine Anton Hansen
Summary: Surface phase diagrams (SPDs) are crucial for understanding the relationship between surface chemistry and reaction conditions. Deriving these diagrams for multi-component systems often requires separate first-principles global optimization tasks. However, we propose a Bayesian evolutionary multitasking (BEM) framework that leverages a unified configurational search space and only requires one expensive electronic structure calculation. This allows for efficient mapping of complex surface systems and has been successfully applied to derive alloy SPDs for heterogeneous catalytic systems.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Optics
Johannes Fiedler, Kim Lefmann, Wolf von Klitzing, Bodil Holst
Summary: Atom and molecule interferometers are widely used in both fundamental research and industrial applications. Most atom interferometers utilize laser beams to create gratings, but they have limitations in terms of wavelength and complexity. In contrast, monolithic interferometers made from single crystals offer nanometer wavelengths and high stability. In this study, we propose a monolithic design for a thermal-beam molecule interferometer based on quantum reflection, and demonstrate its feasibility using Si(111)-H(1 x 1) surfaces as diffractive mirrors for helium atoms.
Article
Chemistry, Physical
Zhenyun Lan, Theresa Isabelle Manguerra Kapunan, Tejs Vegge, Ivano E. Castelli
Summary: This study investigates the structural and electronic properties of double wall MoSTe nanotubes and finds that they have a slightly smaller band gap and exhibit metallic-like behavior, making them promising for electrochemical applications.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Ana-Elena Tutueanu, Machteld E. Kamminga, Tim B. Tejsner, Henrik Jacobsen, Henriette W. Hansen, Monica-Elisabeta Lacatusu, Jacob Baas, Kira L. Eliasen, Jean -Claude Grivel, Yasmine Sassa, Niels Bech Christensen, Paul Steffens, Martin Boehm, Andrea Piovano, Kim Lefmann, Astrid T. Romer
Summary: We conducted triple-axis neutron scattering studies on strongly underdoped La2-xSrxCuO4 (x = 0.05, 0.06, and 0.07) and presented quantitative evidence for a direct competition between low-energy magnetic fluctuations and superconductivity. Three-dimensional superconductivity was found at x = 0.06 and x = 0.07, while only a weak signal of two-dimensional superconductivity in the CuO2 planes was detected at x = 0.05. Surprisingly, we observed a suppression of the low-energy fluctuations by an external magnetic field at all three doping levels, indicating a similar response of two-dimensional superconductivity to a magnetic field as that of a bulk superconductor. Our results provide direct evidence of a gradual onset of superconductivity in cuprates.
Article
Materials Science, Multidisciplinary
Machteld E. Kamminga, Kristine M. L. Krighaar, Astrid T. Romer, Lise O. Sandberg, Pascale P. Deen, Martin Boehm, Genda D. Gu, John M. Tranquada, Kim Lefmann
Summary: We investigated the effect of uniaxial stress on magnetic stripes in the cuprate system La2-xBaxCuO4. The superconducting transition temperature was found to be enhanced under stress. Neutron scattering confirmed that stress suppresses static stripes, suggesting a trade-off between superconductivity and static magnetism. Our results also revealed a displacement of weight from the elastic channel to the inelastic channel and a shift in the momentum of fluctuations towards the typical 1/8 value of commensurability.
Article
Chemistry, Multidisciplinary
Xin Yang, Arghya Bhowmik, Tejs Vegge, Heine Anton Hansen
Summary: The study investigates the reactive process of the oxygen reduction reaction (ORR) at an Au(100)-water interface using uncertainty-aware GNN potentials and enhanced sampling. The trained GNNs show exceptional performance in terms of force prediction accuracy, reproducing structural properties, and low uncertainties. The collective variables employed in this work enable the automatic search of reaction pathways and provide a detailed understanding towards the ORR reaction mechanism on Au(100). The methodology employed in this study can pave the way for modeling complex chemical reactions at electrochemical interfaces with an explicit solvent under ambient conditions.
Article
Materials Science, Multidisciplinary
Machteld E. Kamminga, Jonas Okkels Birk, Jari Hjollum, Henrik Jacobsen, Jakob Lass, Thorbjorn L. Koch, Niels B. Christensen, Christof Niedermayer, Lukas Keller, Luise Theil Kuhn, Elisabeth T. Ulrikkeholm, Erik Brok, Cathrine Frandsen, Kim Lefmann
Summary: By using neutron scattering, we investigated CoO nanoparticles and found the breakdown of the theory of critical phenomena at the nanoscale. Using CoO as a model system, we identified a size-dependent nanocritical temperature region near the antiferromagnetic phase transition, where the magnetic correlation length of the nanoparticles converges to a constant value, significantly smaller than the saturated state observed at low temperatures. This is in clear contrast to the divergence observed in bulk systems around TN. Our finding of nanocriticality in the magnetic phase transition is of great importance for understanding phase transitions at the nanoscale.
Article
Materials Science, Multidisciplinary
Sofie Holm-Janas, Sidse L. Lolk, Anders B. A. Andersen, Tatiana Guidi, David Voneshen, Ivica Zivkovic, Ulla Gro Nielsen, Kim Lefmann
Summary: In this study, the dynamics of the S = 3/2 kagome antiferromagnet KCr3(OD)6(SO4)2 were investigated using neutron spectroscopy. Diffuse spin wave excitations and a kagome zero mode were observed in the ordered phase. The exchange couplings were estimated using linear spin wave theory. Above the critical temperature, diffuse excitations from the classical spin liquid regime dominated.