Gauge-Invariant Excited-State Linear and Quadratic Response Properties within the Meta-Generalized Gradient Approximation

Journal of Chemical Theory and Computation, Год журнала: 2023, Номер 19(15), С. 4897 - 4911

Опубликована: Июль 3, 2023

Gauge invariance is a fundamental symmetry connected to charge conservation and widely accepted as indispensable for any electronic structure method. Hence, the gauge variance of time-dependent kinetic energy density τ used in many meta-generalized gradient approximations (MGGAs) exchange-correlation (XC) functional presents major obstacle applying MGGAs within theory (TDDFT). Replacing by gauge-invariant generalized τ̂ significantly improves accuracy various functionals vertical excitation energies [R. Grotjahn, F. Furche, M. Kaupp. J. Chem. Phys. 2022, 157, 111102]. However, dependence resulting current-MGGAs (cMGGAs) on paramagnetic current gives rise new kernels hyper-kernels ignored previous implementations quadratic higher-order response properties. Here we report first implementation cMGGAs hybrid excited-state gradients dipole moments, well an extension properties including dynamic hyperpolarizabilities two-photon absorption cross sections. In comprehensive benchmark study sections, M06-2X found be superior GGA PBE0. Additionally, two case studies from literature practical prediction nonlinear optical are revisited potential advantages (c)MGGAs compared GGAs discussed. The effect restoring varies depending employed MGGA functional, type excitation, property under investigation: While some individual equilibrium structures affected, average, these changes result marginal improvements when against high-level reference data. Although gauge-variant generally close their counterparts, errors not bounded exceed typical method cases studied. Despite limited effects seen studies, desirable perspective, entail little additional computational cost, necessary consistent with cMGGA linear calculations such energies.

Язык: Английский

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DELFI: a computer oracle for recommending density functionals for excited states calculations

Chemical Science, Год журнала: 2024, Номер 15(12), С. 4489 - 4503

Опубликована: Янв. 1, 2024

DELFI is a computer oracle developed to recommend the exchange-correlation functional be used for given molecule calculate its excited states with time-dependent density theory (TD-DFT).

Язык: Английский

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Compound-tunable embedding potential method to model local electronic excitations on f -element ions in solids: Pilot relativistic coupled cluster study of Ce and Th impurities in yttrium orthophosphate, YPO4

Physical review. B./Physical review. B, Год журнала: 2024, Номер 109(12)

Опубликована: Март 5, 2024

A method to simulate local properties and processes in crystals with impurities via constructing cluster models within the frame of compound-tunable embedding potential (CTEP) highly accurate ab initio relativistic molecular-type electronic structure calculations is developed applied Ce- Th-doped yttrium orthophosphate crystals, ${\mathrm{YPO}}_{4}$, having xenotime structure. Two embedded are considered, ``minimal'' one, ${\mathrm{YO}}_{8}$@${\mathrm{CTEP}}_{\mathrm{min}}$, consisting central ${\mathrm{Y}}^{3+}$ cation its first coordination sphere eight ${\mathrm{O}}^{2\ensuremath{-}}$ anions (i.e., broken P--O bonds), extended counterpart, $\mathrm{Y}{({\mathrm{PO}}_{4})}_{6}$@${\mathrm{CTEP}}_{\mathrm{ext}}$, implying full treatment all atoms ${\mathrm{PO}}_{4}^{3\ensuremath{-}}$ nearest cation. ${\mathrm{CTEP}}_{\mathrm{min},\mathrm{ext}}$ denote here corresponding environment described CTEP method. The Fock space coupled (FS RCC) theory minimal model study excitations localized on ${\mathrm{Ce}}^{3+}$ ${\mathrm{Th}}^{3+}$ impurity ions. Calculated transition energies for cerium-doped a good agreement available experimental data (mean absolute deviation ca. 0.3 eV $4f\ensuremath{\rightarrow}5d$ type transitions). For thorium-doped crystal picture states predicted be quite complicated, ground state expected $6d$ character. uncertainty excitation estimated 0.35 eV. Radiative lifetimes excited calculated at FS RCC level both doped crystals. lifetime lowest $5d$ differs from experimentally measured one by no more than twice.

Язык: Английский

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Performance of Density Functionals for Excited-State Properties of Isolated Chromophores and Exciplexes: Emission Spectra, Solvatochromic Shifts, and Charge-Transfer Character

Journal of Chemical Theory and Computation, Год журнала: 2024, Номер 20(6), С. 2520 - 2537

Опубликована: Март 15, 2024

This study assesses the performance of various meta-generalized gradient approximation (meta-GGA), global hybrid, and range-separated hybrid (RSH) density functionals in capturing excited-state properties organic chromophores their complexes (exciplexes). Motivated by uses solar energy harvesting photoredox CO2 reduction, we use oligo-(p-phenylenes) with triethylamine as model systems. We focus on fluorescence these systems, specifically emission energies. also consider solvatochromic shifts wave function characteristics. The latter is described using reduced quantities such natural transition orbitals (NTOs) exciton descriptors. are benchmarked against experimental spectra equation-of-motion coupled-cluster method single double excitations. Both isolated exciplexes, meta-GGA drastically underestimate energies exhibit significant delocalization anticorrelation between electron hole motion. strongly dependent percentage exact exchange. Our identifies RSH GGAs best-performing functionals, ωPBE demonstrating best agreement results. meta-GGAs often overestimate exciplexes yield larger NTOs. Their can be improved optimally tuning range-separation parameter.

Язык: Английский

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Spurious Oscillations Caused by Density Functional Approximations: Who is to Blame? Exchange or Correlation?

Journal of Chemical Theory and Computation, Год журнала: 2024, Номер 20(8), С. 3144 - 3153

Опубликована: Апрель 3, 2024

We analyze the varying susceptibilities of different density functional approximations (DFAs) to present spurious oscillations on profiles several vibrational properties. Among other problems, these cause significant errors in harmonic and anharmonic IR Raman frequencies intensities. This work hinges a judicious strategy dissect exchange correlation components DFAs pinpoint origins oscillations. identify derivatives all energy with respect nuclear displacements, including those terms that do not involve numerical integrations. These

Язык: Английский

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