Anomalous propagators and the particle–particle channel: Bethe–Salpeter equation

The Journal of Chemical Physics, Journal Year: 2025, Volume and Issue: 162(13)

Published: April 3, 2025

The Bethe-Salpeter equation has been extensively employed to compute the two-body electron-hole propagator and its poles which correspond neutral excitation energies of system. Through a different time-ordering, Green's function can also describe propagation two electrons or holes. corresponding are double ionization potentials electron affinities In this work, for particle-particle is derived within linear-response formalism using pairing field anomalous propagators. This framework allows us kernels self-energy approximations ($GW$, $T$-matrix, second-Born) as in usual case. performance these various gauged singlet triplet valence set 23 small molecules. description core hole states analyzed.

Language: Английский

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Many-Body Effects at Heterogeneous Interfaces from First-Principles: Progress, Challenges, and Opportunities

ACS Nano, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 6, 2025

Heterogeneous interfaces are pivotal in numerous nanoscale devices and applications. First-principles approaches based on quantum mechanics atomistic structures provide critical insights into structure-property relationships, enabling the informed design of materials devices. Accurate first-principles methods must reliably capture many-body effects, i.e., electron-electron interactions, which significantly influence system properties compared to predictions from models using free or noninteracting electrons. In this Perspective, we survey a few computational tools context attempt be forward looking by discussing current challenges emerging research opportunities. We examine diverse manifestations effects across several domains: geometries reaction barriers (total-energy properties), orbital energy levels band alignments (one-particle optical excited states (two-particle properties).

Language: Английский

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Computational and experimental study of terpolymers: spectroscopic, thermal, thermochemical, molecular property, and in silico toxicity analysis

Drug and Chemical Toxicology, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 17

Published: Feb. 28, 2025

In this study, a comprehensive analysis of the CMA2OEM-co-DVB-co-AMPS (2-(bis(cyanomethyl)amino)-2-oxoethyl methacrylate-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propanesulfonic acid) and CMA2OEM-co-DVB-co-VIM methacrylate-co-divinylbenzene-co-vinylimidazole) terpolymers was conducted. The structural chemical properties were examined using Fourier transform infrared (FT-IR) spectroscopy, frontier molecular orbital analysis, electrostatic potential (MEP) maps, 1H, 13C NMR thermochemistry surface maps (TCSM), toxicity assessments, physical properties, electron localization function (ELF), total (ESP) analyses. silico analyses, quantitative structure–activity relationship (QSAR) model used for Toxicity Estimation Software Tool (TEST) ProTox 3.0, web-based virtual laboratory, oral prediction. estimates TEST showed that both exhibited low profiles. Oral prediction emphasizes may pose greater risk compared to CMA2OEM-co-DVB-co-AMPS. addition, experimental thermal characterization these also performed. These analyses have provided significant insights into applications functional terpolymers.

Language: Английский

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Excited-state methods for molecular systems: Performance, pitfalls, and practical guidance

Chemical Physics Reviews, Journal Year: 2025, Volume and Issue: 6(2)

Published: May 1, 2025

Proper theoretical descriptions of ground and excited states are critical for understanding molecular photophysics photochemistry. Complex interactions in experimentally interesting systems require multiple approximations the underlying quantum mechanics to practically solve various physical observables. While high-level calculations small provide very accurate excitation energies, this accuracy does not always extend larger or other properties. Because this, “best” method study new molecules is clear, leading many researchers default inexpensive easy-to-use black-box methods. Unfortunately, even when these methods reproduce experimental it necessarily right reasons. Without physics, becomes challenging understand classes molecules. Consequently, predicted properties their trends may offer reliable mechanistic understanding. This review targeted at beginners computational chemistry who interested studying excited-state A brief overview common ground- covered easy reference during comparison The primary focus compare several important chromophores. performance each explored practitioners a road map on what work well different identify further that needs be done field.

Language: Английский

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Excited-State Hund’s Rule Violations in Bridged [10]- and [14]Annulene Perimeters

The Journal of Physical Chemistry A, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 21, 2024

Molecules with Hund's rule violations between low-lying singlet and triplet states may enable a new generation of fluorescent emitters. However, only few classes molecules are known this property at the current time. Here, we use high-throughput screening algorithm FORMED database to uncover class compounds where first excited state violates rule. We examine bridged [10]- [14]annulene perimeters saturated bridges, relate them conjugated polycyclic systems violations. Despite structural similarities related nonalternant hydrocarbons, mechanism is different in these annulene perimeters. two molecular orbital configurations contribute each state. Consequently, violation can be unambiguously assigned based on symmetry lowest states. With several examples synthetically realistic molecules, [14]annulenes thus provides link alternant (azaphenalene) violating These design principles open avenues for identification types order photophysically relevant inverted.

Language: Английский

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