Best‐Practice DFT Protocols for Basic Molecular Computational Chemistry**

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(42)

Опубликована: Сен. 14, 2022

Nowadays, many chemical investigations are supported by routine calculations of molecular structures, reaction energies, barrier heights, and spectroscopic properties. The lion's share these quantum-chemical applies density functional theory (DFT) evaluated in atomic-orbital basis sets. This work provides best-practice guidance on the numerous methodological technical aspects DFT three parts: Firstly, we set stage introduce a step-by-step decision tree to choose computational protocol that models experiment as closely possible. Secondly, present recommendation matrix guide choice depending task at hand. A particular focus is achieving an optimal balance between accuracy, robustness, efficiency through multi-level approaches. Finally, discuss selected representative examples illustrate recommended protocols effect choices.

Язык: Английский

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A comprehensive electron wavefunction analysis toolbox for chemists, Multiwfn

The Journal of Chemical Physics, Год журнала: 2024, Номер 161(8)

Опубликована: Авг. 27, 2024

Analysis of electron wavefunction is a key component quantum chemistry investigations and indispensable for the practical research many chemical problems. After more than ten years active development, analysis program Multiwfn has accumulated very rich functions, its application scope covered numerous aspects theoretical research, including charge distribution, bond, localization delocalization, aromaticity, intramolecular intermolecular interactions, electronic excitation, response property. This article systematically introduces features functions latest version provides representative examples. Through this article, readers will be able to fully understand characteristics recognize unique value Multiwfn. The source code precompiled executable files Multiwfn, as well manual containing detailed introduction backgrounds tutorials, can all downloaded free from website (http://sobereva.com/multiwfn).

Язык: Английский

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Simple, Efficient, and Universal Energy Decomposition Analysis Method Based on Dispersion-Corrected Density Functional Theory

The Journal of Physical Chemistry A, Год журнала: 2023, Номер 127(33), С. 7023 - 7035

Опубликована: Авг. 15, 2023

Energy decomposition analysis (EDA) is an important class of methods to explore the nature interaction between fragments in a chemical system. It can decompose energy into different physical components understand factors that play key roles interaction. This work proposes EDA strategy based on dispersion-corrected density functional theory (DFT), called sobEDA. method fairly easy implement and very universal. be used study weak interactions, bond open-shell systems, interactions multiple fragments. The total time consumption sobEDA only about twice conventional DFT single-point calculation for entire also variant named sobEDAw, which designed specifically decomposing energies. Through proper combination correlation dispersion correction term, sobEDAw gives ratio electrostatic highly consistent with symmetry-adapted perturbation theory, quite popular robust studying but expensive. We present shell script sobEDA.sh proposed this Gaussian quantum chemistry program Multiwfn wavefunction code. Via script, theoretical chemists use conveniently their study. series examples, rationality new implementation are verified, great practical values various systems demonstrated.

Язык: Английский

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Theoretical Advances in Polariton Chemistry and Molecular Cavity Quantum Electrodynamics

Chemical Reviews, Год журнала: 2023, Номер 123(16), С. 9786 - 9879

Опубликована: Авг. 8, 2023

When molecules are coupled to an optical cavity, new light-matter hybrid states, so-called polaritons, formed due quantum interactions. With the experimental demonstrations of modifying chemical reactivities by forming polaritons under strong interactions, theorists have been encouraged develop methods simulate these systems and discover strategies tune control reactions. This review summarizes some exciting theoretical advances in polariton chemistry, ranging from fundamental framework computational techniques applications spanning photochemistry vibrational coupling. Even though theory interactions goes back midtwentieth century, gaps knowledge molecular electrodynamics (QED) only recently filled. We recent made resolving gauge ambiguities, correct form different QED Hamiltonians gauges, their connections various optics models. Then, we developed ab initio approaches which can accurately describe states a realistic molecule-cavity system. then discuss using method advancements. advancements where cavity is resonant electronic transitions nonadiabatic excited state dynamics enable photochemical reactivities. resonance tuned vibrations instead, ground-state reaction modifications demonstrated experimentally, its mechanistic principle remains unclear. present progress this mystery. Finally, understanding collective coupling regime between light matter, many collectively couple single mode or modes. also lay out current challenges explain observed results. hope that will serve as useful document for anyone who wants become familiar with context chemistry thus significantly benefit entire community.

Язык: Английский

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Revisiting the Performance of Time-Dependent Density Functional Theory for Electronic Excitations: Assessment of 43 Popular and Recently Developed Functionals from Rungs One to Four

Journal of Chemical Theory and Computation, Год журнала: 2022, Номер 18(6), С. 3460 - 3473

Опубликована: Май 9, 2022

In this paper, the performance of more than 40 popular or recently developed density functionals is assessed for calculation 463 vertical excitation energies against large and accurate QuestDB benchmark set. For purpose, Tamm-Dancoff approximation offers a good balance between computational efficiency accuracy. The ωB97X-D BMK are found to offer best overall with root-mean square error (RMSE) around 0.27 eV, better computationally demanding CIS(D) wave function method RMSE 0.36 eV. results also suggest that Jacob's ladder still holds time-dependent functional theory energies, though hybrid meta generalized-gradient approximations (meta-GGAs) not generally GGAs. Effects basis set convergence, gauge invariance correction meta-GGAs, nonlocal correlation (VV10) studied, practical recommendations provided.

Язык: Английский

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Improving Results by Improving Densities: Density-Corrected Density Functional Theory

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(15), С. 6625 - 6639

Опубликована: Апрель 5, 2022

Density functional theory (DFT) calculations have become widespread in both chemistry and materials, because they usually provide useful accuracy at much lower computational cost than wavefunction-based methods. All practical DFT require an approximation to the unknown exchange-correlation energy, which is then used self-consistently Kohn–Sham scheme produce approximate energy from density. Density-corrected simply study of relative contributions total error. In vast majority calculations, error due density negligible. But with certain classes functionals applied problems, sufficiently large as contribute noticeably, its removal leads better results. These problems include reaction barriers, torsional barriers involving π-conjugation, halogen bonds, radicals anions, most stretched etc. all such cases, use a more accurate significantly improves performance, often simple expedient using Hartree–Fock enough. This Perspective explains what DC-DFT is, where it likely improve results, how can functionals. We also outline challenges prospects for field.

Язык: Английский

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Best‐Practice DFT Protocols for Basic Molecular Computational Chemistry**

Angewandte Chemie, Год журнала: 2022, Номер 134(42)

Опубликована: Сен. 14, 2022

Abstract Nowadays, many chemical investigations are supported by routine calculations of molecular structures, reaction energies, barrier heights, and spectroscopic properties. The lion's share these quantum‐chemical applies density functional theory (DFT) evaluated in atomic‐orbital basis sets. This work provides best‐practice guidance on the numerous methodological technical aspects DFT three parts: Firstly, we set stage introduce a step‐by‐step decision tree to choose computational protocol that models experiment as closely possible. Secondly, present recommendation matrix guide choice depending task at hand. A particular focus is achieving an optimal balance between accuracy, robustness, efficiency through multi‐level approaches. Finally, discuss selected representative examples illustrate recommended protocols effect choices.

Язык: Английский

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FCclasses3: Vibrationally‐resolved spectra simulated at the edge of the harmonic approximation

Journal of Computational Chemistry, Год журнала: 2022, Номер 44(4), С. 626 - 643

Опубликована: Ноя. 15, 2022

We introduce FCclasses3, a code to carry out vibronic simulations of electronic spectra and nonradiative rates, based on the harmonic approximation. Key new features are: implementation full family vertical adiabatic models, vibrational analysis in curvilinear coordinates, extension several spectroscopies time-dependent approaches. The use valence internal coordinates allows adoption quadratic model potential energy surfaces (PES) initial final states expanded at arbitrary configurations. Moreover, suitable projectors provides robust framework for defining reduced-dimensionality models by sorting flexible subset, so that they can then be treated anharmonic level, or with mixed quantum classical A set tools facilitate input preparation output is also provided. show program work simulation different (one two-photon absorption, emission resonance Raman) conversion rate typical rigid molecule, anthracene. Then, we focus absorption series polyphenyl molecules, highlighting relevance some newly implemented features. freely available http://www.iccom.cnr.it/en/fcclasses/.

Язык: Английский

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Reversible spin-optical interface in luminescent organic radicals

Nature, Год журнала: 2023, Номер 620(7974), С. 538 - 544

Опубликована: Авг. 16, 2023

Abstract Molecules present a versatile platform for quantum information science 1,2 and are candidates sensing computation applications 3,4 . Robust spin-optical interfaces key to harnessing the resources of materials 5 To date, carbon-based have been non-luminescent 6,7 , which prevents optical readout via emission. Here we report organic molecules showing both efficient luminescence near-unity generation yield excited states with spin multiplicity S > 1. This was achieved by designing an energy resonance between emissive doublet triplet levels, here on covalently coupled tris(2,4,6-trichlorophenyl) methyl-carbazole radicals anthracene. We observed that photoexcitation delocalized onto linked acene within few picoseconds subsequently evolved pure high-spin state (quartet monoradical, quintet biradical) mixed radical–triplet character near 1.8 eV. These coherently addressable microwaves even at 295 K, enabled reverse intersystem crossing states. Furthermore, biradical, return ground previously uncorrelated radical spins either side anthracene shows strong correlation. Our approach simultaneously supports high efficiency initialization, manipulations light-based room temperature. The integration creates emerging technologies.

Язык: Английский

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Spin–phonon coupling and magnetic relaxation in single-molecule magnets

Chemical Society Reviews, Год журнала: 2023, Номер 52(14), С. 4567 - 4585

Опубликована: Янв. 1, 2023

Electron–phonon coupling underlies many physical phenomena, but its microscopic origins are nuanced. This Review derives the spin–phonon interactions in molecules from first principles, and describes an implementation for molecular spin dynamics calculations.

Язык: Английский

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