Article
Nanoscience & Nanotechnology
Ji Il Choi, Han Seul Kim, Young-Jun Sohn, Sung-Dae Yim, Faisal M. Alamgir, Seung Soon Jang
Summary: Based on recent studies, an epitaxial monolayer of Pt on graphene exhibits enhanced catalytic activity and unprecedented stability for the oxygen reduction reaction. The unique reactivity of the Pt and graphene surfaces, as well as their different mechanisms for ORR, contribute to the improved performance of the hybrid catalyst system.
ACS APPLIED NANO MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Chenglong Qin, Yushu Yu, Zihan Xu, Jiguang Du, Liang Zhao, Gang Jiang
Summary: The reactions between gamma-U (001) and (110) surfaces and O2 were studied using density functional theory (DFT), ab initio thermodynamic methods, and ab initio molecular dynamics simulations (AIMD). The adsorption, dissociation, and diffusion of O2 on the surfaces were investigated. The research provides insights into surface oxidation corrosion and suggests an initial process of surface corrosion involving O2 physical adsorption, dissociation, surface diffusion, and subsurface penetration.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Chemistry, Physical
Mahdi Soltani Nejad, Mojtaba Alipour
Summary: Oscillator strength is an important quantity in atomic and molecular spectroscopy, directly related to the intensity of peaks in UV-visible spectra. Accurately calculating oscillator strengths remains a challenge. This study thoroughly investigates the oscillator strengths in the electronic spectra of organic compounds using optimally tuned range-separated hybrids. The proposed methods show superior performance in predicting oscillator strengths compared to traditional methods and earlier range-separated functionals.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Physics, Multidisciplinary
Vivekanand Shukla, Yang Jiao, Jung-Hoon Lee, Elsebeth Schroeder, Jeffrey B. Neaton, Per Hyldgaard
Summary: We introduce a new general-purpose van der Waals density functional, vdW-DF2-ahbr, which combines vdW-DF2 correlation with a screened Fock exchange. It successfully resolves spurious exchange binding and density-driven errors, significantly improving the performance of existing vdW-DFs for molecular problems.
Article
Chemistry, Multidisciplinary
Ho Viet Thang
Summary: Doping heteroatoms is an effective method for enhancing the electronic properties of ZnO materials for desired applications. This study investigates the effects of different dopant metals on the electronic and adsorption properties of ZnO(1010) using DFT + U calculations. The research shows that Cu dopant significantly enhances the adsorption characteristics of ZnO materials. This study will be beneficial for designing appropriate materials for adsorption and catalytic applications.
Article
Materials Science, Multidisciplinary
Kyle R. Stoltz, Elena Echeverria, Amrit Kaphle, Aaron J. Austin, Parameswar Harikumar, Andrew J. Yost, David N. McIlroy, Mario F. Borunda
Summary: In this study, the energetically favorable configuration in Co-doped ZnO nanostructures was found to be clusters of CoO, through calculating the total energy of system configurations and fitting experimental data.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
Oscar Hurtado-Aular, Rafael Anez, Anibal Sierraalta
Summary: This study investigates the adsorption behavior of Cu, Ag, or Au on the surface of WO3, as well as the adsorption of CO molecules. The results show that the adsorption of Cu, Ag, and Au atoms induces changes in the surface electronic structure, while the adsorption of CO leads to a reduction in band gap. The findings provide insights for the potential applications of WO3 in gas sensing chemistry and photocatalysis.
Article
Chemistry, Physical
Shang Jiang, Samir H. Mushrif
Summary: In this study, the surface-specific U values for NiO and Co3O4 were determined using XPS and DFT+U methods, and adsorbates corresponding to experimentally observed XPS shifts were identified. These findings are important for analyzing experimental XPS data and accurately predicting adsorption and reaction energetics on these catalysts.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Yeongsu Cho, Aditya Nandy, Chenru Duan, Heather J. Kulik
Summary: High-level multireference (MR) methods are necessary for systems with complex wave functions that cannot be described by a single determinant. This study applies low-cost MR diagnostics, based on fractional occupation numbers calculated with finite-temperature DFT, to solid-state systems for the first time. The results demonstrate that the DFT-based MR diagnostics are equally applicable to solids as to their molecular derivatives, providing a more affordable alternative for characterizing the electronic structure of solids.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Multidisciplinary
Keith K. L. Husted, Christopher M. Brown, Peyton Shieh, Ilia Kevlishvili, Samantha L. Kristufek, Hadiqa Zafar, Joseph V. Accardo, Julian C. Cooper, Rebekka S. Klausen, Heather J. Kulik, Jeffrey S. Moore, Nancy R. Sottos, Julia A. Kalow, Jeremiah A. Johnson
Summary: Researchers have discovered that bifunctional silyl ether-based comonomers, catalyzed by low-cost food-safe catalyst octanoic acid, can generate covalent adaptable network analogues of industrial thermoset polydicyclopentadiene. These materials exhibit temperature- and time-dependent stress relaxation and can be remolded. This study introduces acid-catalyzed BSE exchange as a new approach for crosslinking commercial thermosets.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Gianmarco G. Terrones, Chenru Duan, Aditya Nandy, Heather J. Kulik
Summary: Using low-cost machine learning models and experimental data, we accurately predict the excited state properties of photoactive iridium complexes. These properties include the mean emission energy, excited state lifetime, and emission spectral integral. Our models, trained on electronic structure features from low-cost density functional tight binding calculations, outperform traditional ab initio methods such as time-dependent density functional theory (TDDFT). We also identify the correlation between ligand ionization potential and the predicted properties.
Article
Multidisciplinary Sciences
Colin Y. Kim, Andrew J. Mitchell, David W. Kastner, Claire E. Albright, Michael A. Gutierrez, Christopher M. Glinkerman, Heather J. Kulik, Jing-Ke Weng
Summary: This study reveals the unconventional catalytic mechanism of COSY, a BAHD acyltransferase-family enzyme, in accelerating coumarin synthesis through a proton exchange mechanism.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Shuwen Yue, Changhwan Oh, Aditya Nandy, Gianmarco G. Terrones, Heather J. Kulik
Summary: The flexible degrees of freedom in metal-organic frameworks (MOFs) can significantly affect guest molecule behavior. However, most molecular simulation studies assume rigid frameworks to minimize computational cost. In this study, we assess the importance of this assumption on methane uptake and diffusion in UiO-66 using functionalization and linker rotation. We find that linker rotation has a moderate impact on methane uptake and a significant impact on methane diffusion. Our assessment provides uncertainty ranges for these properties associated with linker rotation and identifies void volume fraction and minimum pore size as governing factors. These findings demonstrate the impact of linker rotation on MOFs and provide design principles for future investigations.
MOLECULAR SYSTEMS DESIGN & ENGINEERING
(2023)
Article
Chemistry, Physical
Aditya Nandy, Michael G. Taylor, Heather J. Kulik
Summary: We surveyed a large number of crystallized mononuclear transition metal complexes to analyze trends in geometric structure and metal coordination. While an increased electron filling generally correlates with a lower coordination number preference, there are exceptions. We also found underrepresentation of 4d/5d transition metals and 3p-coordinating ligands. Among the octahedral complexes, analysis of their ligand environments revealed the presence of removable monodentate ligands, creating reactive sites amenable to catalysis. By analyzing tetradentate ligands, we identified potential catalysts that co-occur with labile monodentate ligands in crystallized complexes.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Husain Adamji, Aditya Nandy, Ilia Kevlishvili, Yuriy Roman-Leshkov, Heather J. Kulik
Summary: The study focuses on the direct partial oxidation of methane to methanol using metal-organic frameworks (MOFs). By developing a high-throughput virtual screening workflow, researchers identified three promising Mn MOFs for methane-to-methanol conversion. These MOFs exhibit favorable kinetics and thermodynamics, indicating their potential for further experimental catalytic studies.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Vyshnavi Vennelakanti, Michael G. Taylor, Aditya Nandy, Chenru Duan, Heather J. Kulik
Summary: In this study, the electronic and Gibbs free energies associated with spin crossover in 95 Fe(II) SCO complexes were investigated using density functional theory (DFT) with 30 different functionals. It was found that a modified version of B3LYP, M06-L, and TPSSh functionals accurately predict the spin crossover behavior of most complexes, while the MN15-L functional fails to predict any spin crossover behavior.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Freya Edholm, Aditya Nandy, Clorice R. Reinhardt, David W. Kastner, Heather J. Kulik
Summary: Metalloenzymes are enzymes that catalyze a wide range of chemical reactions, and the residues in their active sites play a crucial role in regulating the reactivity and selectivity of these reactions. This study introduces a method to analyze metal binding sites and demonstrates its application in analyzing metal-containing active sites in proteins.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Xin He, Andrei Iliescu, Tzuhsiung Yang, Maxx Q. Arguilla, Tianyang Chen, Heather J. Kulik, Mircea Dinca
Summary: The article introduces a self-assembled tetramanganese cluster that can reversibly reduce O-2 by four electrons and facilitate the interconversion between molecular O-2 and metal-oxo species.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Polymer Science
Kelsie E. Wentz, Yunxin Yao, Ilia Kevlishvili, Tatiana B. Kouznetsova, Braden A. Mediavilla, Heather J. Kulik, Stephen L. Craig, Rebekka S. Klausen
Summary: Four unsaturated poly(carbooligosilane)s were synthesized by acyclic diene metathesis polycondensation of new oligosilane diene monomers. These polymers showed high trans internal olefin stereochemistry and molecular weights, and were further modified through postpolymerization epoxidation for single-molecule force spectroscopy studies. The single-chain elasticity of the polycarbooligosilanes decreased with increasing numbers of Si-Si bonds, as supported by quantum chemical calculations.
Article
Materials Science, Multidisciplinary
Aditya Nandy, Shuwen Yue, Changhwan Oh, Chenru Duan, Gianmarco G. Terrones, Yongchul G. Chung, Heather J. Kulik
Summary: High-throughput screening of hypothetical metal-organic framework (MOF) databases allows for the discovery of new materials with unknown stability in real-world applications. By leveraging community knowledge and machine learning (ML) models, we have identified MOFs that are both thermally stable and stable upon activation. We have created a new hypothetical MOF database with over 50,000 structures, orders of magnitude more connectivity nets and inorganic building blocks than previous databases, and a significant enrichment of ultrastable MOF structures.
Article
Chemistry, Physical
Yael Cytter, Aditya Nandy, Chenru Duan, Heather J. Kulik
Summary: Virtual high-throughput screening (VHTS) and machine learning (ML) with density functional theory (DFT) suffer from inaccuracies from the underlying density functional approximation (DFA). We computed and analyzed the average curvature for 23 density functional approximations and trained ML models to predict the curvature and frontier orbital energies for each functional. Spin was found to play a more important role in determining the curvature of certain DFAs, and our models helped accelerate the screening of complexes with targeted optical gaps.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Chenru Duan, Aditya Nandy, Ralf Meyer, Naveen Arunachalam, Heather J. Kulik
Summary: Approximate density functional theory is essential for its balanced cost-accuracy trade-off, but no DFA with universal accuracy has been identified. We develop a DFA recommender using electron density fitting and Delta-learning, which selects the DFA with the lowest expected error based on system-specific evaluation. Our recommender achieves excellent accuracy in predicting top-performing DFAs for chemical discovery, outperforming existing models and approaches.
NATURE COMPUTATIONAL SCIENCE
(2023)
Article
Chemistry, Inorganic & Nuclear
Vyshnavi Vennelakanti, Grace L. Li, Heather J. Kulik
Summary: Selective halogenation plays an important role in fine chemical applications, but C-H fluorination faces challenges. In this study, computational calculations reveal differences in structural and energetic preferences between fluoride and chloride/bromide intermediates throughout the catalytic cycle. The possibility of isomerization playing a role in reaction selectivity differences is also investigated. The study provides potential steps towards engineering nonheme iron halogenases for selective C-H fluorination.
INORGANIC CHEMISTRY
(2023)