Article
Chemistry, Applied
Lin Xiao, Shang Wang, Yi Wang, Binchen Wang, Chaofan Ji, Xinping Lin, Huipeng Liang, Sufang Zhang, Xianbing Xu, Liang Dong
Summary: Volatile profiling of oleic acid oxidation was analyzed using thermal desorption cryo-trapping combined with gas chromatography-mass spectrometry. A total of 43 volatile compounds were identified, and the oxidative mechanism of oleic acid was explored using density functional theory. The results revealed 30 reactions categorized into peroxide, alkoxy radical, and peroxide radical pathways, with branch chemical reactions playing a key role.
Article
Chemistry, Organic
Theodoros Mikroulis, M. Consuelo Cuquerella, Angelo Giussani, Anna Pantelia, Gemma M. Rodriguez-Muniz, Georgios Rotas, Daniel Roca-Sanjuan, Miguel A. Miranda, Georgios C. Vougioukalakis
Summary: Luminol, a prominent chemiluminescent agent, is widely used in various fields and its chemiluminescence efficiency can be modulated by different substitution patterns on the aromatic ring. A systematic study on the synthesis and photophysics of 6,8-disubstituted luminol derivatives was conducted to identify the architecture with optimum chemiluminescence efficiency, leading to the synthesis of a novel highly efficient luminol derivative. Complementary work on fluorescence and quantum chemistry computations was employed to rationalize the observed results.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Paul B. Calio, Donald G. Truhlar, Laura Gagliardi
Summary: We present the first implementation of multiconfiguration pair-density functional theory (MC-PDFT) ab initio molecular dynamics, which has similar or even better accuracy compared to complete active space second-order perturbation theory (CASPT2) but at a lower computational cost. Our implementation of MC-PDFT into the SHARC molecular dynamics program for ab initio, nonadiabatic molecular dynamics simulations is verified through the examination of the intersystem crossing dynamics of thioformaldehyde, showing excellent agreement with CASPT2 and experimental findings. Furthermore, MC-PDFT enables dynamics simulations with large active spaces that were computationally expensive with CASPT2.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Multidisciplinary
Felippe Mariano Colombari, Viviane Marcos Nascimento, Yi Ling Liu, George Jackson de Morais Rocha, Carlos Driemeier
Summary: In this study, SMD-DFT method was used to calculate the solvation free energy (delta G(solv)) for 283 neutral lignin depolymerization fragments and analogues in water and organic solvents. The results showed that the calculated delta G(solv) in water outperformed the accuracy of the FreeSolv benchmark, and for organic solvents, the SMD-DFT calculations could accurately predict the partition coefficients after accounting for systematic biases due to solvent admixtures.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Physical
Philippe F. F. Weck, Carlos F. F. Jove-Colon, Eunja Kim
Summary: Polymorphism and phase transitions in sodium diuranate (Na2U2O7) are investigated using density functional perturbation theory (DFPT). The thermal properties of different polymorphs of Na2U2O7 are predicted for the first time, and the energetically degenerate behavior of the alpha and beta phases is observed. Gibbs free energy calculations reveal that there is no direct solid-solid phase transition between the beta and gamma phases at high temperatures, suggesting a multi-step process involving beta-phase decomposition and recrystallization into the gamma phase. These findings are consistent with experimental observations.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Nobuki Inoue, Yoshihiro Watanabe, Haruyuki Nakano
Summary: The article provides theoretical discussions on issues in relativistic molecular orbital theory applied to the quantum electrodynamics (QED) Hamiltonian. Several QED Hamiltonians previously proposed are evaluated based on orbital rotation invariance, charge conjugation and time reversal invariance, and nonrelativistic limit. A new total energy expression is proposed to prevent total energy divergence caused by electron correlations. The article also reintroduces the Dirac-Hartree-Fock (DHF) and electron correlation methods based on the Hamiltonian and energy expression.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Multidisciplinary Sciences
Zejie Fei, Jia-Qi Wang, Rulin Tang, Yuzhu Lu, Changcai Han, Yongtian Wang, Jing Hong, Changwu Dong, Han-Shi Hu, Xiao-Gen Xiong, Chuangang Ning, Hongtao Liu, Jun Li
Summary: Through joint photoelectron spectroscopy and quantum chemical study, researchers have discovered a quadruple bond between nitrogen and thorium in thorium nitride. This quadruple bond is comprised of two electron-sharing π bonds and one directional σ bond, with an additional weak σ bonding interaction.
NATURE COMMUNICATIONS
(2023)
Review
Chemistry, Physical
Prachi Sharma, Jie J. Bao, Donald G. Truhlar, Laura Gagliardi
Summary: Kohn-Sham density functional theory is less accurate for strongly correlated systems compared to weakly correlated systems. The available functionals for spin densities do not accurately predict energies for strongly correlated systems when using multiconfigurational wave functions with spin symmetry. Multiconfiguration pair-density functional theory overcomes these limitations by using a functional of the total density and on-top pair density, allowing efficient calculation of energy for strongly correlated systems.
ANNUAL REVIEW OF PHYSICAL CHEMISTRY, VOL 72
(2021)
Article
Food Science & Technology
Tong Wang, Ning Wang, Minghao Wang, Liqi Wang, Yongge Shi, Jing Du, Dianyu Yu
Summary: Density functional theory (DFT) was used to simulate the degradation of A9-tetrahydrocannabinol (A9-THC) in hemp seed oil, and ultrasonic treatment was applied to degrade A9-THC. The results showed that the degradation of A9-THC to cannabinol (CBN) was a spontaneous exothermic reaction. Through electrostatic potential and molecular orbital analysis, it was found that A9-THC had stronger reactivity and required a certain amount of external energy to initiate the degradation process. Ultrasonic treatment effectively degraded A9-THC into CBN in both standard solution and hemp seed oil.
FOOD RESEARCH INTERNATIONAL
(2023)
Article
Chemistry, Physical
Ruth H. Tichauer, Dmitry Morozov, Ilia Sokolovskii, J. Jussi Toppari, Gerrit Groenhof
Summary: This study uses multiscale molecular dynamics simulations to investigate the relaxation process of polaritons in tetracene molecules strongly coupled to confined light modes. The results indicate that the relaxation involves vibrationally assisted scattering (VAS) and radiative pumping (RP), both driven by the same molecular vibrations through nonadiabatic coupling between dark states and polaritonic states.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Multidisciplinary Sciences
Junxu Li, Barbara A. Jones, Sabre Kais
Summary: Perturbation theory is a powerful tool for approximate solutions to complex problems by starting from the exact solution of a simpler problem. Advances in quantum computing have provided opportunities for alternatives to classical methods. We present a general quantum circuit that estimates both energy and eigenstates corrections, which outperforms the classical version in estimating second-order energy corrections. Our work offers a general approach to studying complex systems with quantum devices and can be applied to other Hamiltonian systems in chemistry and physics.
Article
Multidisciplinary Sciences
Johannes T. Margraf, Karsten Reuter
Summary: Density-functional theory is a rigorous framework for describing the ground state properties of atoms, molecules and solids, while a new machine-learning based DFA called Kernel Density Functional Approximation has been developed, which is pure, non-local and transferable, showing remarkable possibilities for diverse interactions and system sizes.
NATURE COMMUNICATIONS
(2021)
Review
Chemistry, Multidisciplinary
Jon G. C. Kragskow, Andrea Mattioni, Jakob K. Staab, Daniel Reta, Jonathan M. Skelton, Nicholas F. Chilton
Summary: Electron-phonon coupling plays a crucial role in various physical phenomena, such as photosynthesis, catalysis, and quantum information processing. One area of significant interest is the study of single-molecule magnets for the miniaturization of binary data storage media. Progress in synthetic organometallic chemistry has led to the observation of molecular magnetic memory effects at higher temperatures. However, understanding the interplay between phonons and molecular spin states is still a challenge. This Tutorial Review aims to introduce the topics of phonons, molecular spin-phonon coupling, and magnetic relaxation, and to outline relevant theories using traditional perturbative approaches and modern open quantum systems methods.
CHEMICAL SOCIETY REVIEWS
(2023)
Article
Computer Science, Interdisciplinary Applications
Honghui Shang, WanZhen Liang, Yunquan Zhang, Jinlong Yang
Summary: A new method for calculating response properties related to atomic displacement and electric field perturbation, based on real-space density-functional perturbation theory (DFPT), has been developed and implemented. The computation bottleneck of the response density matrix has been identified and a more efficient algorithm has been proposed, reducing the formal scaling from O(N-3) to O(N) with good parallel scalability. Validation has shown rapid and accurate computation of polarizabilities using DFPT, with computational efficiency demonstrated on massively parallel computer systems.
COMPUTER PHYSICS COMMUNICATIONS
(2021)
Review
Physics, Multidisciplinary
Marcela Pelaez, Urko Reinosa, Julien Serreau, Matthieu Tissier, Nicolas Wschebor
Summary: Lattice simulations in the Landau gauge have shown that the coupling constant in the QCD sector remains finite and moderate at all scales, while the gluon propagator reaches a finite nonzero value at vanishing momentum. Studies have successfully described infrared QCD dynamics using the perturbative Curci-Ferrari model, with calculations showing good agreement with lattice simulations. The approach has also been applied to scenarios with dynamical quarks, showing controlled approximation schemes can account for chiral symmetry breaking. Applications to nonzero temperature and chemical potential have also been explored.
REPORTS ON PROGRESS IN PHYSICS
(2021)
Article
Mathematics, Applied
Eric Cances, Nahia Mourad
COMMUNICATIONS IN APPLIED MATHEMATICS AND COMPUTATIONAL SCIENCE
(2018)
Article
Computer Science, Information Systems
Hassan A. Alsattar, Sarah Qahtan, Nahia Mourad, A. A. Zaidan, Muhammet Deveci, Chiranjibe Jana, Weiping Ding
Summary: Sustainable smart living is a crucial component in the emergence of smart cities, and this study introduces a novel decision-making method to assess different frameworks and determine the best one through ranking and grading.
INFORMATION SCIENCES
(2023)
Article
Management
Ahmed Mohamed Habib, Nahia Mourad
Summary: This study develops a robust model to measure intellectual capital efficiency (ICE) and analyzes differences in ICE across Gulf companies, sectors and countries.
BENCHMARKING-AN INTERNATIONAL JOURNAL
(2023)
Article
Operations Research & Management Science
Nahia Mourad, Ahmed Mohamed Habib, Assem Tharwat
Summary: This study aimed to assess the performance of healthcare systems in countries with over fifty million citizens in facing the COVID-19 pandemic. The findings revealed that less than half of the countries considered were relatively efficient, with the main impact being on efficiency scores from the number of affected and recovered cases. The study emphasizes the importance of achieving relative efficiency in healthcare systems.
DECISION SCIENCE LETTERS
(2021)
Article
Mathematics, Applied
Eric Cances, Nahia Mourad
COMMUNICATIONS IN MATHEMATICAL SCIENCES
(2016)
