Article
Chemistry, Physical
Shiqi Ruan, Koblar A. Jackson, Adrienn Ruzsinszky
Summary: Complexes with transition metal atoms in a 3d(4)-3d(7) electron configuration typically have two low-lying states, high-spin (HS) and low-spin (LS). The accuracy of electronic structure approximations for the spin-crossover energies of iron complexes with different ligands is analyzed in this study. It is found that evaluating non-empirical exchange-correlation energy functionals on self-interaction corrected densities improves the accuracy of the adiabatic energy differences between HS and LS states.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Navaratnarajah Kuganathan, Nicholas J. Barron, Robin W. Grimes
Summary: The incorporation of volatile fission products in UN and PuN is examined using atomic scale density functional theory calculations. Preference for specific incorporation sites in the nitrides is determined by the size of the fission products. Comparison between UN and PuN suggests a preference for PuN due to its larger lattice parameter. Furthermore, there are significant differences in fission product retention behavior between oxides and nitrides.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Jonathan Tanti, Nikolas Kaltsoyannis
Summary: This study analyzed the substitutions of tetravalent early actinides (Th - Am) and Ce into zirconolite, CaZrTi2O7, using hybrid Density Functional Theory and the Periodic Electrostatic Embedded Cluster Method. The redox behavior was confirmed through analysis of spin density data, with strong correlations found between substitution energies and ionic radii ratios. Similar behaviors were observed for Ce4+ and Pu4+ substitutions, with a preference for the +3 oxidation state in later actinides.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Chemistry, Inorganic & Nuclear
Nicholas Greaves, Nikolas Kaltsoyannis
Summary: The geometries, electronic structures, and spin state energetics of multi-layer Matryoshka actinyl peroxide manganese nanoclusters have been studied using generalised gradient approximation and hybrid density functional theory. Strong linear correlations were found between the number of unpaired electrons and the energies of the complexes, with the highest spin states being the most stable. The compositions of molecular orbitals associated with changing spin states were studied in detail, providing insight into the relative energies of different spin states.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Xiao Tan, Suitao Qi, Rui Hua, Chunhai Yi, Bolun Yang
Summary: The study investigated the adsorption and dissociation pathways of NO on different crystal surfaces of beta-MnO2, with results indicating that NO prefers to adsorb on the beta-MnO2(110) surface, showing stronger interaction and more charge transfer compared to the (101) surface. The lower energy barrier for NO dissociation on beta-MnO2(110) is attributed to bridge adsorption of NO and increased electron transfer, facilitating N-O bond breaking.
APPLIED SURFACE SCIENCE
(2021)
Article
Biochemistry & Molecular Biology
Pavel S. Lemport, Valentine S. Petrov, Petr I. Matveev, Uliana M. Leksina, Vitaly A. Roznyatovsky, Igor P. Gloriozov, Alexandr V. Yatsenko, Viktor A. Tafeenko, Pavel V. Dorovatovskii, Viktor N. Khrustalev, Gleb S. Budylin, Evgeny A. Shirshin, Vitaliy Yu. Markov, Alexey A. Goryunkov, Vladimir G. Petrov, Yuri A. Ustynyuk, Valentine G. Nenajdenko
Summary: The reaction of acyl chlorides derived from 1,10-phenanthroline-2,9-dicarboxylic acids with piperazine allows the preparation of 24-membered macrocycles in good yield. These new macrocyclic ligands have promising coordination properties towards f-elements, particularly Am and Eu. They exhibit higher extraction efficiency for Am(III) compared to calixarene-type extraction, and the composition of the macrocycle-metal complex with Eu(III) has been investigated.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Multidisciplinary
Arunasis Bhattacharyya, Avinash S. Kanekar, Richard J. M. Egberink, Willem Verboom, Jurriaan Huskens, Prasanta K. Mohapatra
Summary: Two diglycolamide (DGA) derivatives with different alkyl chain branching, n-butyl (nBuDGA) and s-butyl (sBuDGA), were used to extract Am3+ and Eu3+ ions. The selectivity between Am3+ and Eu3+ reversed with the change in ligand from nBuDGA to sBuDGA, and a reverse trend was observed for the extraction of lanthanide ions with decreasing ionic radii. Luminescence and FTIR studies suggested different nature of Eu3+ complexes of these two ligands. DFT studies provided insights into the structure and electronic distribution of Am3+ and Eu3+ complexes of these two ligands.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Physical
Lin Yang, Nikolas Kaltsoyannis
Summary: Density functional theory was used to study intrinsic point defects and incorporation of fission gas atoms Kr and Xe in uranium nitride. The results showed that defect formation energies are highly dependent on stoichiometry. The incorporation of Kr and Xe induces relaxation of the atomic positions in UN, with Xe causing more significant displacement than Kr due to its larger atomic radius.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Shilong Gao, Anuvab Das, Edwin Alfonzo, Kathleen M. Sicinski, Dominic Rieger, Frances H. Arnold
Summary: Activating hydroxylamine for nitrene transfer offers a cost-effective and sustainable route to amine synthesis. An engineered heme enzyme was developed that utilizes hydroxylammonium chloride for nitrene transfer, enabling efficient benzylic C-H primary amination and styrene aminohydroxylation. This study contributes to the repertoire of nitrene transferases and suggests the potential discovery of natural enzymes using hydroxylamine for amination chemistry.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Xun-Jian Hu, Yi Yang, Chunju Hou, Tong-Xiang Liang
Summary: Perovskite oxides are versatile materials with rich properties, and recent research has shown that freestanding two-dimensional structures down to the monolayer limit can be prepared. The study reveals that 2D perovskite oxides exhibit abnormal band-gap trends, with a gap value lower than the bulk limit, indicating the presence of an unusual quantum size effect. The electronic properties of 2D perovskite oxides evolve with dimension change, with termination-dependent thermodynamic stability and band splitting contributing to the abnormal trends.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Zhigang Ni, Yang Guo, Frank Neese, Wei Li, Shuhua Li
Summary: The paper introduces a cluster-in-molecule (CIM) local correlation approach with an accurate distant pair correlation energy correction, which is crucial for predicting absolute correlation energies and relative energies in large systems. Benchmark calculations demonstrate that the improved CIM approach can recover over 99.94% of the correlation energy calculated by the parent method, providing accurate binding energies for weakly bound complexes of varying sizes.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
Angel Albavera-Mata, S. B. Trickey, Richard G. Hennig
Summary: This study demonstrates a method for improving the accuracy of calculating spin-crossover energies, and proposes a set of recommended averaged Ueff values for high-throughput calculations.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Joshua P. Hinz, Valentin V. Karasiev, S. X. Hu, Deyan I. Mihaylov
Summary: In this paper, Delta learning is used to map orbital-free density functional theory (DFT) ionic forces to the corresponding Kohn-Sham (KS) DFT ionic forces. The approximate force difference in terms of the ion positions is developed and acts as a substitute for the ground truth force difference. Descriptor vectors are constructed for ion configurations using all distances between ions and an indexing based on nearest neighbor ranking. It is demonstrated that this descriptor scheme can uniquely describe an ionic configuration up to rotation and reflection when there is no ambiguity in the nearest neighbor ranking. The handling of ambiguous nearest neighbor ranking is also discussed. As a proof of principle, the model is trained and tested on warm dense hydrogen at temperatures ranging from 1 to 15 eV. After testing, the model is used to perform molecular dynamic simulations of warm dense hydrogen, with resulting energies and pressures within 1-2% of their respective target KS values.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Navaratnarajah Kuganathan, Alexander Chroneos
Summary: LiPON is a candidate solid electrolyte material for rechargeable lithium-ion batteries, with density functional theory simulations providing insight into defect properties, dopant solutions, and lithium incorporation. The Schottky defect is the most favorable disorder process in this material, facilitating the formation of Li and O vacancies necessary for vacancy-mediated self-diffusion.
COMPUTATIONAL MATERIALS SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Ivana Zrinski, Marvin Loeefler, Janez Zavasnik, Claudia Cancellieri, Lars P. H. Jeurgens, Achim Walter Hassel, Andrei Ionut Mardare
Summary: The aim of this study was to develop memristors based on Nb2O5 by a simple and inexpensive electrochemical anodization process. It was found that the selection of electrolyte played an important role in resistive switching. Anodic memristors grown in phosphate buffer showed improved electrical characteristics, while those formed in citrated buffer exhibited excellent memory capabilities. The chemical composition of oxides was successfully determined using HAXPES and their phase composition and crystal structure were evaluated by TEM.
Article
Physics, Condensed Matter
Aleksandr Lushchik, Vladimir N. Kuzovkov, Irina Kudryavtseva, Anatoli I. Popov, Viktor Seeman, Evgeni Shablonin, Evgeni Vasil'chenko, Eugene A. Kotomin
Summary: This study analyzed the thermal stability and recombination kinetics of primary anion Frenkel defects in fast-neutron-irradiated alpha-Al2O3 single crystals, and demonstrated for the first time the coexistence of two types of oxygen interstitials. The diffusion parameters of these interstitials were obtained, which are crucial for predicting secondary defect-induced reactions and thermal stability of the material.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2022)
Article
Physics, Applied
R. I. Eglitis, E. A. Kotomin, A. I. Popov, S. P. Kruchinin, Ran Jia
Summary: The paper presents the results of ab initio calculations for the surfaces of perovskites SrTiO3, BaTiO3, PbTiO3, and SrZrO3. It shows that the upper layer atoms relax inwards towards the bulk on the (001) surface, and the second layer atoms relax upwards. The surface energies for AO and BO2-terminations on the (001) surfaces are almost equal, while the surface energies for AO(3) and B-terminated (111) surfaces are quite different.
LOW TEMPERATURE PHYSICS
(2022)
Correction
Instruments & Instrumentation
Eugene A. Kotomin
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2022)
Article
Physics, Condensed Matter
Eugene A. Kotomin, Alexei Kuzmin, Juris Purans, Janis Timoshenko, Sergei Piskunov, Rotraut Merkle, Joachim Maier
Summary: A comparative study of isoelectronic CaFeO3 and SrFeO3 perovskites was conducted using ab initio quantum chemical calculations and X-ray absorption spectroscopy. Results showed agreement with previous findings, supporting a cubic structure for SrFeO3 and a transition from orthorhombic to monoclinic structure in CaFeO3. Discussions on local atomic and magnetic structures, as well as electronic properties, were presented in detail.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2022)
Article
Chemistry, Physical
Davis Zavickis, Guntars Zvejnieks, Andrei Chesnokov, Denis Gryaznov
Summary: In this study, we employ hybrid B1WC density functional calculations and the supercell model to investigate the properties of BaCoO3 with corner-sharing CoO6 octahedral geometry. We compare the atomic and electronic structures of ideal and defective BaCoO3 containing a single oxygen vacancy (Vo). The ideal BaCoO3 is better described by the triclinic space group (SG) P1 supercell, while the defective BaCoO3 is characterized by the formation energy of Vo of 0.4 eV in the low symmetry Pmm2 model.
SOLID STATE IONICS
(2022)
Article
Chemistry, Physical
Yuri A. Mastrikov, Denis Gryaznov, Maksim N. Sokolov, Guntars Zvejnieks, Anatoli Popov, Roberts Eglitis, Eugene A. Kotomin, Maxim Ananyev
Summary: The atomic structure of antiphase boundaries in Sr-doped lanthanum scandate (La1-xSrxScO3-delta) perovskite was modeled using DFT method. Two structural types of interfaces were studied, and it was found that both types are stable and promote oxygen ion migration.
Article
Electrochemistry
Milda Petruleviciene, Jurgis Pilipavicius, Jurga Juodkazyte, Denis Gryaznov, Linas Vilciauskas
Summary: In this study, NASICON-structured Na3-xV2-xTix(PO4)(3) materials were successfully synthesized and shown to have improved charge capacity and cycling stability in aqueous Na-ion battery. The presence of titanium stabilizes the NASICON structure and its content directly affects the aqueous stability. The capacity loss in symmetric cells is caused by the capacity imbalance between positive and negative electrodes, mainly due to the oxygen reduction reaction catalyzed by Ti(III). Mitigation of this reaction can enhance the cycling stability of the battery.
ELECTROCHIMICA ACTA
(2022)
Article
Chemistry, Physical
Yu-Yang Tai, Jeffrey C. S. Wu, Wen-Yueh Yu, Marjeta Macek Krzmanc, Eugene Kotomin
Summary: A core-shell structural Rh-CrOx loaded on Al3+ doped strontium titanate was used for simultaneous photocatalytic degradation of isopropanol and hydrogen production. A specially designed twin photoreactor was utilized, and with the help of an electron-mediator and an anion-exchanged membrane, high amounts of hydrogen gas were evolved through photocatalytic water splitting under simulated sunlight. The rate-limiting H2 rate was successfully overcome, indicating the potential of this system for efficient hydrogen production.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Physical
N. V. Krainyukova, V. O. Hamalii, L. L. Rusevich, E. A. Kotomin, J. Maier
Summary: Reflection high-energy electron diffraction revealed multiple surface structural transformations accompanied by an 'in-plane' lattice parameter growth on SrTiO3 single crystal surface. These transformations occur over temperature intervals separated by relaxed zones where no structural changes occur. The 'in-plane' contraction of the crystal lattice and higher thermal expansion on the surface compared to the bulk were experimentally and theoretically confirmed. This contradicts the assumption that surface 'in-plane' and bulk lattice parameters are identical.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Yu-Guan Lee, Yu-Ching Cheng, Yu-Tang Lin, Jeffrey C. S. Wu, Wen-Yueh Yu, Marjeta Macek Krzmanc, Suraj Gupta, Eugene Kotomin
Summary: Photocatalytic water splitting is a promising approach for converting solar energy into green hydrogen. This study investigated the combinatorial effect of molten salts and Al doping on the performance of SrTiO3-based catalysts for water splitting. The results showed that Al-doped Rh (x) Cr2-x O3/SrTiO3 synthesized using KCl molten salt exhibited the highest hydrogen evolution rate and photocatalytic activity. Moreover, loading core-shell Rh (x) Cr2-x O3 using in situ photodeposition further enhanced the hydrogen evolution rates under different light sources.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Denis Gryaznov, Linas Vilciauskas
Summary: The electronic structure and properties of NASICON-structured A(4)V(2)(PO4)(3) were studied using hybrid density functional theory calculations. The symmetries and band structures of Li4V2(PO4)(3), Na4V2(PO4)(3), and K4V2(PO4)(3) were analyzed. Li4V2(PO4)(3) and Na4V2(PO4)(3) had monoclinic structures with an average vanadium oxidation state of V+2.5, while K4V2(PO4)(3) had a monoclinic structure with mixed vanadium oxidation states of V+2/V+3. Li4V2(PO4)(3) and Na4V2(PO4)(3) exhibited metallic states due to increased symmetry, except for Na4V2(PO4)(3) with an averaged oxidation state of R32. K4V2(PO4)(3) retained a small band gap in all configurations. These findings provide valuable insights for crystallography and electronic structure investigations of these materials.
Article
Chemistry, Physical
Veera Krasnenko, Alexander Platonenko, Aleksandr Liivand, Leonid L. Rusevich, Yuri A. Mastrikov, Guntars Zvejnieks, Maksim Sokolov, Eugene A. Kotomin
Summary: This study used DFT methods to model the Raman spectra of ultra-thin strontium titanate (STO) films, revealing differences in features compared to bulk crystals and frequency shifts with increasing film thickness.
Article
Multidisciplinary Sciences
Guntars Zvejnieks, Yuri Mastrikov, Denis Gryaznov
Summary: We present a theoretical justification for the distorted Ruddlesden-Popper (RP) phases through hybrid density functional theory (DFT) calculations and group-theoretical analysis. We demonstrate the existence of the Jahn-Teller effect in Sr2FeO4. Through comparison of three hybrid DFT functionals, we have established a three-parameter functional WC3PW, which accurately describes Sr2FeO4. We explain the conditions for co-existing proper and pseudo-Jahn-Teller effects using crystalline orbitals, symmetry-mode analysis, and irreps products. Phonon frequency calculations support and confirm the results of symmetry-mode analysis. Additionally, we provide diffraction patterns to discuss the differences between the two crystal symmetries.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Physical
M. F. Hoedl, A. Chesnokov, D. Gryaznov, R. Merkle, E. A. Kotomin, J. Maier
Summary: Proton migration in the triple conducting perovskite BaFeO3-delta was investigated using first-principles density functional theory calculations. The migration pathways of protons were determined by lattice distortions caused by oxygen vacancies in oxygen-deficient BaFeO3-delta. The average migration barrier for proton transfer in the Jahn-Teller distorted BaFeO3 was calculated to be 0.22 eV. The decrease in migration barrier with increasing oxygen deficiency in BaFeO2.75 was attributed to the annihilation of oxygen holes rather than to volume expansion upon reduction.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Instruments & Instrumentation
Taisei Hayashi, Kensei Ichiba, Daisuke Nakauchi, Takumi Kato, Noriaki Kawaguchi, Takayuki Yanagida
Summary: In this study, Cr-doped Mg4Ta2O9 single crystals with different doping levels were synthesized using the floating zone method, and their photoluminescence and scintillation properties were evaluated. The results showed that Cr-doped Mg4Ta2O9 single crystals exhibited broad emission bands in the near-infrared region and showed scintillation characteristics within specific wavelength ranges. Additionally, the samples with different Cr doping levels demonstrated different lower detection limits based on the dose rate response function.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
S. Marouf, A. C. Chami, Y. Boudouma
Summary: This study develops a Monte Carlo simulation approach to describe proton-induced secondary electron emission in solids. Theoretical modeling based on the Mott's elastic scattering cross-section and Lindhard's dielectric function was used to calculate the double differential cross-section (DDCS) of excited electrons and describe electron transport in the medium. The results for aluminum show the angular and energy distributions of backscattered electrons for incident protons with energy below 25 keV at normal incidence, and the total electron emission yield also agrees well with available measurements.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
Weipeng Yan, Baojun Duan, Zijian Zhu, Yan Song, Guzhou Song, Jiming Ma, Binkang Li, Yucheng Liu
Summary: This article reports on the scintillation performance of Lithium-doped 2D (PEA)2PbBr4 perovskite single crystals synthesized at room temperature. The crystals exhibit fast decay time, high light yield, and high spatial resolution, making them highly promising for medical diagnostic applications.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
S. B. Vishwakarma, S. K. Dubey, R. L. Dubey, I. Sulania, D. Kanjilal
Summary: Investigations have been conducted on the implanted SiO2 thin film after thermal annealing using various analytical techniques. The results revealed the absence of vacancy defects, variations in vibrational modes and the formation of new structures. The photoluminescence intensity of the annealed SiO2 samples was higher, with a decrease in non-radiative defect centers and an increase in radiative Si:SiO2 interface states. Additionally, the presence of silicon nanoclusters formed after annealing resulted in an additional radiative recombination peak. Furthermore, the formation of new SiOx structures was observed after thermal annealing.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
M. Koshimizu, S. Kurashima, A. Kimura, M. Taguchi
Summary: By observing the scintillation time profiles of CeF3 under irradiations of pulsed beams with different LETs, we found that the initial decay was faster for higher LET, which is consistent with previous studies on other self-activated scintillators. This faster decay at higher LET can be explained by the competition between the scintillation caused by 5d-4f transition of Ce3+ ions and quenching due to the interaction between excited Ce3+ ions close to each other.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
Junjie Shi, Jianhong Hao, Fang Zhang, Qiang Zhao, Bixi Xue, Jieqing Fan, Zhiwei Dong
Summary: This study examined the neutralization process and beam quality of a hydrogen beam by emitting negative hydrogen ions to a hydrogen target. The findings showed that the neutralization efficiency was influenced by variables such as the transport distance, energy, and target gas density. However, the maximal neutralization efficiency was not affected by the density of the target gas or the energy of the negative hydrogen ions.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
