Article
Biochemistry & Molecular Biology
Meagan S. Oakley, Laura Gagliardi, Donald G. Truhlar
Summary: The study utilized CAS and SP wave functions to simulate the bond dissociation of transition metal silicides and predict experimental results, with typical errors of 0.2 eV and 0.3 eV, respectively. The ground and low-lying excited states were explored to predict state ordering for each molecule, and potential energy curves were calculated for comparison to experimental results. English Summary: The study utilized CAS and SP wave functions to simulate the bond dissociation of transition metal silicides and predict experimental results, with typical errors of 0.2 eV and 0.3 eV, respectively.
Article
Chemistry, Multidisciplinary
Mohammadreza Izadifar, Neven Ukrainczyk, Eduardus Koenders
Summary: In this study, a method was proposed to compute the activation energies required for the dissolution of metakaolin (MK) at far-from-equilibrium conditions using the improved dimer method and the transition-state theory within density functional theory. The results showed that the activation energy for breaking the oxo-bridging bond between silicate or aluminate units is higher for the former due to the ionic interaction. However, a higher activation energy is required for breaking the oxo-bridging bond to the aluminate neighbor compared to the silicate neighbor for complete silicate tetrahedra dissolution. These findings can provide missing input data for predicting the mesoscopic dissolution rate using the atomistic kinetic Monte Carlo upscaling approach.
Article
Environmental Sciences
Zehong Li, Wei Zhang, Zhaohui Chen, Zhaoying Ren, Shuo Ning, Mengting Li
Summary: Using advanced quantum chemistry methods, this study explores the pathways of NOX formation and reduction and determines new kinetic parameters. Energy barrier analysis reveals that NO is mainly produced through a sequence of reactions rather than the traditional reaction. The formation of NO2 depends largely on O and HO2 radicals, while the active O atom promotes both the formation and destruction of NO2.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Chemistry, Physical
Zhi-Yao Wang, Zhi-Gang Fang, Jie Wang, Li-E Liu, Ting-Hui Wu, Jia Song
Summary: In this study, density functional theory and transition state theory methods were used to investigate the isomerization transition of the cluster ConMoS (n = 1-5). The results revealed eight isomerization reactions for the clusters ConMoS (n = 3, 5). It was found that the forward reaction had a greater propensity for isomerization transformation compared to the reverse reaction.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Sebastian Kozuch, Amir Karton, Said Jalife, Gabriel Merino
Summary: The 21-homododecahedryl cation is a unique system with complete fluxionality based on two different rearrangements. Quantum tunneling effects are reported to drive reactions at temperatures where classical kinetics are impossible. It is theorized that the tunnel effect in this system could be used to create a refrigerator operating at arbitrarily low temperatures.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Satoru Fukuhara, Kristof M. Bal, Erik C. Neyts, Yasushi Shibuta
Summary: Advanced molecular dynamics simulations and metadynamics simulations were used to construct the free energy surface for carbon segregation in nickel nanoparticles, revealing the relative stability of different stages and the free energy barriers and rates of individual steps. With an increase in carbon concentration, segregated carbon becomes more stable in terms of both enthalpy and entropy.
Article
Chemistry, Physical
Wenfeng Wu, Xianlong Wang, Zhi Zeng
Summary: Based on the hybrid functional, a study on CsV3Sb5 reveals that it exhibits a magnetic moment of 0.28 mu(B) per vanadium atom at 0 GPa, which is suppressed by a spin-crossover phenomenon at a pressure of 2.5 GPa. The non-magnetic ground state of CsV3Sb5 with CDW distortion leads to the suppression of the magnetic moment of vanadium atoms at 94 K due to temperature-induced CDW transition. At low temperature, CsV3Sb5 is a rare example of materials with pressure-induced magnetic moment, emphasizing the importance of considering the effects of magnetic moments of vanadium atoms in understanding its properties.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Multidisciplinary Sciences
Yifan Wang, Wei Cai
Summary: This study reveals the microscopic mechanisms of cross-slip of screw dislocations in crystalline solids using molecular dynamics simulation and identifies the influence of anharmonic effects. This finding contributes to a better understanding of stress-driven thermally activated processes in solids.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Chemistry, Physical
Chi Zhang, Xiurong Yang, Zihan Zhang, Jiachen Li, Wujing Jin, Haixia Ma
Summary: In this study, the decomposition mechanism of ammonium perchlorate (AP) on graphitic carbon nitride (g-C3N4) catalyst was investigated using density functional theory calculation. The main decomposition pathway of AP was found to be HClO4 -> ClO3- -> ClO2- -> ClO- -> Cl-. Additionally, the oxidation of g-C3N4 surface weakened its catalytic capacity for AP decomposition but enhanced its catalytic capacity for the adsorption and dehydrogenation of NH3.
SURFACES AND INTERFACES
(2022)
Article
Chemistry, Physical
Bin Yu, Qiu He, Yan Zhao
Summary: Metal phthalocyanines (MPc) can effectively anchor LiPSs, accelerate the decomposition of Li2S, and promote sulfur reduction reactions. Among these, TiPc performs the best in anchoring LiPSs, accelerating the decomposition of Li2S, and promoting sulfur reduction reactions.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Alexander R. Epstein, Jeremy Demarteau, Brett A. Helms, Kristin A. Persson
Summary: The design of circular polymers is necessary due to the lack of efficient recycling methods for many commodity plastics. Polydiketoenamines (PDKs) stand out for their ability to undergo selective depolymerization in strong acid, allowing monomers to be recovered. The chemistry of the cross-linker, far from the reaction center, has been found to affect the depolymerization rate of PDKs, with a proximal amine in the cross-linker significantly accelerating the process.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Environmental Sciences
Ruisi Huang, Hongyu Cao, Ting Huang, Hongjiang Li, Qian Tang, Lihao Wang, Xuefang Zheng
Summary: The abuse of fluoroquinolones antibiotics causes resistance and pollution. This study investigates the photodegradation mechanisms and environmental factors affecting the degradation of fleroxacin. Six possible photodegradation reaction paths were proposed and simulated. The main reactions involve the departure of the piperazine ring and the substitution of fluorine atom. Factors such as pH and substances like NaN3 and Ca2+ were found to influence the photodegradation process.
Article
Engineering, Chemical
Vladislav Pavluchkov, Idit Shefer, Ophir Peer-Haim, Jens Blotevogel, Razi Epsztein
Summary: Recent studies have identified the significant role of ion dehydration in the permeation of small ions through polyamide membranes. In this study, the researchers quantified the intrinsic permeability and activation enthalpy and entropy for a variety of ions in polyamide nanofiltration membranes. The results showed a correlation between hydration strength and enthalpic barrier, with smaller bare ions experiencing smaller entropic losses after dehydration. The measured activation enthalpies suggested that ions are only partially dehydrated. Additionally, simulations at higher temperatures and experimental results in a pressure-driven system revealed higher permeation rates and reversed ion-ion selectivity, indicating the activation of ion transport through ion dehydration when additional energy is supplied.
JOURNAL OF MEMBRANE SCIENCE
(2022)
Article
Biochemistry & Molecular Biology
Merve Demirtas, Hande Ustunel, Daniele Toffoli
Summary: The catalytic activity of gold can be enhanced by introducing other metals to its surface. In this study, the effect of Pt doping on the catalytic activity of a Au(111) surface for methanol dehydrogenation was investigated using first-principles density functional theory. It was found that Pt surface doping significantly decreases the activation energy barrier of this reaction.
Article
Chemistry, Physical
Sebastian Ovalle, Cecile Malardier-Jugroot
Summary: Simultaneous prediction of the geometries, spin states, and binding energies of iron porphyrins using DFT methods is challenging. In this study, six functionals and three basis sets were tested, and the B97D functional with basis set A was found to provide accurate geometries, correct spin states, and good binding energies for the heme model. This study provides valuable information for selecting suitable DFT methods for studying small iron porphyrins and their interaction with oxygen.
COMPUTATIONAL AND THEORETICAL CHEMISTRY
(2022)
