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The periodic table has always contributed to the discovery of a number of elements. Is there no such principle for larger-scale substances than atoms? Many stable substances such as clusters have been predicted based on the jellium model, which usually assumes that their structures are approximately spherical. The jellium model is effective to explain subglobular clusters such as icosahedral clusters. To broaden the scope of this model, we propose the symmetry-adapted orbital model, which explicitly takes into account the level splittings of the electronic orbitals due to lower structural symmetries. This refinement indicates the possibility of an abundance of stable clusters with various shapes that obey a certain periodicity. Many existing substances are also governed by the same rule. Consequently, all substances with the same symmetry can be unified into a periodic framework in analogy to the periodic table of elements, which will act as a useful compass to find missing substances.
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http://dx.doi.org/10.1038/s41467-019-11649-0 | DOI Listing |
J Chem Theory Comput
September 2025
University of Warsaw, Faculty of Chemistry, ul. L. Pasteura 1, 02-093 Warsaw, Poland.
We extend first-order multiconfigurational symmetry-adapted perturbation theory, SAPT(MC), [Hapka, M. 2021, 17, 5538-5555], to account for double-exchange effects, where up to two electron pairs are exchanged between interacting monomers. To achieve this, we derive density-matrix-based expressions for the first-order exchange energy to arbitrary orders in the overlap expansion.
View Article and Find Full Text PDFJ Chem Phys
June 2025
Institute for Drug Research, School of Pharmacy, Ein Kerem Campus, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
Classical valence bond (VB) theory has advanced significantly in recent years, evolving into a quantitative tool comparable to molecular orbital-based methods. A key advantage of VB is its high interpretability through Lewis-like resonance structures. However, traditional VB theory faces challenges with symmetric systems, as it often fails to generate symmetric sets of structures, leading to a loss of wavefunction interpretability.
View Article and Find Full Text PDFActa Crystallogr A Found Adv
July 2025
Department of Physics, Faculty of Science and Technology, University of the Basque Country/Euskal Herriko Unibertsitatea (UPV/EHU), Bilbao, Spain.
Spin space groups, formed by operations where the rotation of the spins is independent of the accompanying operation acting on the crystal structure, are appropriate groups to describe the symmetry of magnetic structures with null spin-orbit coupling. Their corresponding spin point groups are the symmetry groups to be considered for deriving the symmetry constraints on the form of the crystal tensor properties of such idealized structures. These groups can also be taken as approximate symmetries (with some restrictions) of real magnetic structures, where spin-orbit coupling and magnetic anisotropy are however present.
View Article and Find Full Text PDFJ Am Chem Soc
April 2025
Department of Chemistry, University of Washington, Seattle, Washington 98195, United States.
The structural and chemical bonding motifs manifested by the competition between hydrogen and chalcogen bonding in the homodimers of chalcogen hydrides (HX), where X = O, S, Se, Te have been characterized using high-level electronic structure calculations and analysis of the electron density based on Quasi-atomic orbital (QUAO) and the Symmetry-adapted perturbation theory (SAPT) methods. The QUAO analysis clearly identifies a three-center interaction responsible for either hydrogen or chalcogen bonds: in the former, the σ-bond connecting the donor and hydrogen atom participating in the hydrogen bond interacts with the lone pair on the nucleophile acceptor via the hydrogen atom, while in the latter this same σ-bond interacts with the nucleophile lone pair via the donor chalcogen. The number of minimum energy structures increase dramatically from one for (HO), three for (HS), four for (HSe), and finally six for (HTe).
View Article and Find Full Text PDFJ Mol Graph Model
June 2025
Department of Chemistry, Technical University of Denmark, 2800, Kongens Lyngby, Denmark. Electronic address:
The potential of a novel thiazole-modified covalent triazine framework (S-CTF) as surface for the adsorption and sensing of the carcinogenic metabolites acrylamide (AM), 2-amino-3,8-dimethylimidazo-[4,5-f]quinoxaline (MEIQX), 2-amino-1-methyl-6-phenylimidazole[4,5-f]pyridine (PhlP) and 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) is explored. The selectivity, sensitivity, and adsorption properties of the S-CTF surface are investigated through noncovalent interaction (NCI), quantum theory of atoms in molecules (QTAIM) and symmetry adapted perturbation theory (SAPT0) analyses. All the analytes were found to be physiosorbed on the surface of the sensor with the following strength of interaction: MEIQX@S-CTF = PhlP@S-CTF > Trp-P-1@S-CTF > AM@S-CTF.
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