Thermochemistry of Species in Gas-Phase Thermal Oxidation of C₂ to C₈ Perfluorinated Carboxylic Acids

The Journal of Physical Chemistry A, Journal Year: 2024, Volume and Issue: 128(7), P. 1313 - 1326

Published: Feb. 9, 2024

New thermochemical properties,

Language: Английский

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The performance and efficiency of twelve range-separated hybrid DFT functionals for calculation of the magnetic exchange coupling constants of di-nuclear first row transition metal complexes

Computational and Theoretical Chemistry, Journal Year: 2024, Volume and Issue: 1235, P. 114541 - 114541

Published: March 5, 2024

The performance and efficiency of twelve range-separated hybrid functionals are compared with each other in calculating magnetic exchange coupling constant (J) data on eleven di-nuclear first-row transition metal complexes having di-copper (Cu) di-vanadium (V) as their central atoms. J values then the experimental findings. In addition to that we also computed B3LYP results these complexes. We them obtained from well understand performances predicting constant. When computing, reoptimized all structures taken crystal data, Js were determined. predicted terms four statistical error matrices, namely, mean absolute (MAE), fractional (MFE), signed (MSE), root square (RMSE) cm−1.

Language: Английский

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Dispersion-corrected r2SCAN based double-hybrid functionals

The Journal of Chemical Physics, Journal Year: 2023, Volume and Issue: 159(22)

Published: Dec. 8, 2023

The regularized and restored semi-local meta-generalized gradient approximation (meta-GGA) exchange-correlation functional r2SCAN [Furness et al., J. Phys. Chem. Lett. 11, 8208-8215 (2020)] is used to create adiabatic-connection-derived global double-hybrid functionals employing spin-opposite-scaled MP2. 0-DH, CIDH, QIDH, 0-2 type are assessed as a starting point for further modification. Variants with 50% 69% Hartree-Fock exchange (HFX) empirically optimized (Pr2SCAN50 Pr2SCAN69), the effect of MP2-regularization (κPr2SCAN50) range-separated HFX (ωPr2SCAN50) evaluated. All combined state-of-the-art London dispersion corrections D4 NL. resulting comprehensively their performance on main-group metal-organic thermochemistry 90 different benchmark sets containing 25 800 data points. These include extensive GMTKN55 database, additional chemistry, multiple transition-metal complexes, including ROST61, MOR41, MOBH35 sets. As main target this study development broadly applicable, robust low empiricism, special focus put variants moderate amounts (50%), which compared so far successful PWPB95-D4 (50% HFX, 20% MP2 correlation) functional. overall best variant, ωPr2SCAN50-D4, performs well thermochemistry, followed by Pr2SCAN69-D4 that offers slight edge Pr2SCAN50-D4 robustly across all tested four functionals, Pr2SCAN69-D4, Pr2SCAN50-D4, κPr2SCAN50-D4, outperform

Language: Английский

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Combined DFT and Kinetic Monte Carlo Study of UiO-66 Catalysts for γ-Valerolactone Production

The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: 128(3), P. 1049 - 1057

Published: Jan. 12, 2024

Zr-based metal–organic frameworks (MOFs) are excellent heterogeneous porous catalysts due to their thermal stability. Their tunability via node and linker modifications makes them amenable for theoretical studies on catalyst design. However, detailed benchmarks MOF-based reaction mechanisms combined with kinetics analysis still scarce. Thus, we here evaluate different computational models density functional theory (DFT) methods followed by kinetic Monte Carlo a case relevant in biomass upgrading, i.e., the conversion of methyl levulinate γ-valerolactone catalyzed UiO-66. We show impact cluster versus periodic models, importance DF choice, direct comparison experimental data simulated data. Overall, found that Perdew–Burke–Ernzerhof (PBE), widely employed method plane-wave calculations, greatly overestimates rates, while M06 better fits available is recommended whenever possible.

Language: Английский

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Modeling Multi-Step Organic Reactions: Can Density Functional Theory Deliver Misleading Chemistry?

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(10), P. 6721 - 6732

Published: Feb. 27, 2024

Many organic reactions are characterized by a complex mechanism with variety of transition states and intermediates different chemical natures. Their correct accurate theoretical characterization critically depends on the accuracy computational method used. In this work, we study ambimodal cycloaddition five states, two intermediates, three products, ask whether density functional theory (DFT) can provide description type multifaceted reaction. Our work fills gap in that most systematic benchmarks DFT for have considered much simpler reactions. results show many functionals not only lead to seriously large errors but also differ from one another predicting reaction is ambimodal. Only few available balanced The parameters varied tested ingredients, treatment medium-range nonlocal correlation energy, inclusion Hartree–Fock exchange. These clear need more mechanisms molecules

Language: Английский

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Exploring factors affecting the dissociation energies of C–O and C–C bonds in lignin oligomers

Chemical Engineering Science, Journal Year: 2024, Volume and Issue: 297, P. 120296 - 120296

Published: May 31, 2024

Language: Английский

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Multireference calculations on bond dissociation and biradical polycyclic aromatic hydrocarbons as guidance for fractional occupation number weighted density analysis in DFT calculations

Theoretical Chemistry Accounts, Journal Year: 2024, Volume and Issue: 143(10)

Published: Sept. 27, 2024

Language: Английский

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Improving the Reliability of, and Confidence in, DFT Functional Benchmarking through Active Learning

Journal of Chemical Theory and Computation, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 2, 2025

Validating the performance of exchange-correlation functionals is vital to ensure reliability density functional theory (DFT) calculations. Typically, these validations involve benchmarking data sets. Currently, such sets are usually assembled in an unprincipled manner, suffering from uncontrolled chemical bias, and limiting transferability results a broader space. In this work, data-efficient solution based on active learning explored address issue. Focusing─as proof principle─on pericyclic reactions, we start BH9 set design reaction space around initial by combinatorially combining templates substituents. Next, surrogate model trained predict standard deviation activation energies computed across selection 20 distinct DFT functionals. With model, designed explored, enabling identification challenging regions, i.e., regions with large divergence, for which representative reactions subsequently acquired as additional training points. Remarkably, it turns out that function mapping molecular structure divergence readily learnable; convergence reached upon acquisition fewer than 100 reactions. our final updated more challenging─and arguably representative─pericyclic curated, demonstrate has changed significantly compared original subset.

Language: Английский

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Modulation of the Product Upon the Reaction of CO₂ With Dimethylamine Cluster: A Topological Analysis of the Reaction Mechanism

Journal of Computational Chemistry, Journal Year: 2025, Volume and Issue: 46(13)

Published: May 14, 2025

ABSTRACT The capture, activation, and reaction of carbon dioxide with dimethylamine (DMA) clusters have been investigated theoretically in the gas phase. electronic structure various compounds has obtained using density functional theory approach. partitioning path into different domains structural stability done within framework electron localization function (ELF) analysis. It found that DMA cluster size is a key parameter modulating CO 2 conversion, both energetically structurally. shown as increases, hidden transform real energy barrier for rate‐limiting step significantly decreases, so slow unlikely becomes an instantaneous viable reaction. Carbamic acid hydrogen bonded dimer unique product trimer.

Language: Английский

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A comparative assessment of density functional approximations for inner reorganization energy: insights from small molecules models with varying degrees of charge delocalization

Theoretical Chemistry Accounts, Journal Year: 2025, Volume and Issue: 144(6)

Published: May 16, 2025

Language: Английский

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