Computer simulations are invaluable for the study of ultrafast phenomena, as they allow us to directly access the electron dynamics. We present an efficient method for simulating the evolution of electrons in molecules under the influence of time-dependent electric fields, based on the Gaussian tight binding model. This model improves upon standard self-charge-consistent tight binding by the inclusion of polarizable orbitals and a self-consistent description of charge multipoles. Using the examples of bithiophene, terthiophene, and tetrathiophene, we show that this model produces electrostatic, electrodynamic, and explicitly time-dependent properties in strong agreement with density-functional theory, but at a small fraction of the cost.
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http://dx.doi.org/10.1063/1.4995611 | DOI Listing |
Nat Commun
January 2025
Key Laboratory of Automobile Materials, Ministry of Education, Department of Materials Science and Engineering, Jilin University, 130022, Changchun, China.
Correlating the bond strength with the macro strength of metals is crucial for understanding mechanical properties and designing multi-principal-element alloys (MPEAs). Motivated by the role of grain boundaries in the strength of metals, we introduce a predictive model to determine the grain-boundary energies and strength of metals from the cohesive energy and atomic radius. This scheme originates from the d-band characteristics and broken-bond spirit of tight-binding models, and demonstrates that the repulsive/attractive effects play different roles in the variation of bond strength for different metals.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
Machine learning interatomic potentials (MLIPs) promise quantum-level accuracy at classical force field speeds, but their performance hinges on the quality and diversity of training data. An efficient and fully automated approach to sample chemical reaction space without relying on human intuition, addressing a critical gap in MLIP development is presented. The method combines the speed of tight-binding calculations with selective high-level refinement, generating diverse datasets that capture both equilibrium and reactive regions of potential energy surfaces.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Physics, Institute for Sustainable Energy and Environment, Virginia Commonwealth University, Richmond, VA, 23284, USA.
We propose a new stable three-dimensional (3D) porous and metallic boron nitride anode material, named h-BN, with good ductility for sodium-ion batteries (SIBs). Based on first-principles calculations and a tight-binding model, we demonstrate that the metallicity originates from the synergistic contribution of the p-orbital of the sp-hybridized B and N atoms, while the ductility is due to the unique configurations of B-B and N-N dimers in the structure. More importantly, this boron nitride allotrope exhibits a high reversible capacity of 582.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Nikolaev Institute of Inorganic Chemistry SB RAS, 3 Lavrentiev Pr., 630090 Novosibirsk, Russia.
This paper presents the results of quantum-chemical modeling performed by the Density Functional-Based Tight Binding (DFTB) method to investigate the change in the band structure of hybrid materials based on carbon nanotubes and unsubstituted, tetra-, or octa-halogen-substituted zinc phthalocyanines upon the adsorption of ammonia molecules. The study showed that the electrical conductivity of these materials and its changes in the case of interaction with ammonia molecules depend on the position of the impurity band formed by the orbitals of macrocycle atoms relative to the forbidden energy gap of the hybrids. The sensor response of the hybrids containing halogenated phthalocyanines was lower by one or two orders of magnitude, depending on the number of substituents, compared to the hybrid with unsubstituted zinc phthalocyanine.
View Article and Find Full Text PDFJ Biol Chem
January 2025
Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, United States. Electronic address:
Cytochrome P450 (P450) 4A11 is a human P450 family 4 ω-oxidase that selectively catalyzes the hydroxylation of the terminal methyl group of fatty acids. Cytosolic lipids are the substrates for the enzyme but are considered to be primarily bound in cells by liver fatty acid binding protein (FABP1). Lipid binding to recombinant FABP1 with a fluorophore displacement assay showed substantial preference of FABP1 for ≥16-carbon fatty acids (K < 70 nM).
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