A larger basis set describes atomization energy core–valence correction better than a higher-order coupled-cluster method

Chamkin, Aleksandr A.; Chamkina, Elena S.

doi:10.1039/d3cp03893a

Cited by 2 publications

(2 citation statements)

References 64 publications

(125 reference statements)

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“…On the other hand, in the case of the CC(t;3) and UBCCD(T) approaches, the HOC (TQ) CC energy correction to Δ E might have a smaller impact with larger than double-ζ basis sets. 122 Therefore, one can speculate that, with the mixed-ζ VXZ Dunning’s basis sets, the extrapolated CC estimates of Δ E set a lower limit in the case of ex-CC(t;3)-HOC and ex-UBCCD(T)-HOC, and an upper limit in the case of ex-LR-CCSD(T)-HOC.…”

Section: Computational Detailsmentioning

confidence: 98%

“…In other words, with the all-electron Dunning’s basis sets, the HOC corrected ex-LR-CCSD(T) Δ E misses in practice quadruple corrections and rather represents the canonical perturbative triples result only. On the other hand, in the case of the CC(t;3) and UBCCD(T) approaches, the HOC (TQ) CC energy correction to Δ E might have a smaller impact with larger than double-ζ basis sets . Therefore, one can speculate that, with the mixed-ζ VXZ Dunning’s basis sets, the extrapolated CC estimates of Δ E set a lower limit in the case of ex-CC(t;3)-HOC and ex-UBCCD(T)-HOC, and an upper limit in the case of ex-LR-CCSD(T)-HOC.…”

Section: Computational Detailsmentioning

confidence: 99%

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Scalar Relativistic All-Electron and Pseudopotential Ab Initio Study of a Minimal Nitrogenase [Fe(SH)₄H]⁻ Model Employing Coupled-Cluster and Auxiliary-Field Quantum Monte Carlo Many-Body Methods

Vysotskiy,

Filippi,

Ryde

2024

J. Phys. Chem. A

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Nitrogenase is the only enzyme that can cleave the triple bond in N 2 , making nitrogen available to organisms. The detailed mechanism of this enzyme is currently not known, and computational studies are complicated by the fact that different density functional theory (DFT) methods give very different energetic results for calculations involving nitrogenase models. Recently, we designed a [Fe(SH) 4 H] − model with the fifth proton binding either to Fe or S to mimic different possible protonation states of the nitrogenase active site. We showed that the energy difference between these two isomers (ΔE) is hard to estimate with quantum-mechanical methods. Based on nonrelativistic single-reference coupled-cluster (CC) calculations, we estimated that the ΔE is 101 kJ/mol. In this study, we demonstrate that scalar relativistic effects play an important role and significantly affect ΔE. Our best revised single-reference CC estimates for ΔE are 85−91 kJ/mol, including energy corrections to account for contributions beyond triples, core−valence correlation, and basis-set incompleteness error. Among coupled-cluster approaches with approximate triples, the canonical CCSD(T) exhibits the largest error for this problem. Complementary to CC, we also used phaseless auxiliary-field quantum Monte Carlo calculations (ph-AFQMC). We show that with a Hartree−Fock (HF) trial wave function, ph-AFQMC reproduces the CC results within 5 ± 1 kJ/mol. With multi-Slater-determinant (MSD) trials, the results are 82−84 ± 2 kJ/mol, indicating that multireference effects may be rather modest. Among the DFT methods tested, τ-HCTH, r 2 SCAN with 10−13% HF exchange with and without dispersion, and O3LYP/O3LYP-D4, and B3LYP*/B3LYP*-D4 generally perform the best. The r 2 SCAN12 (with 12% HF exchange) functional mimics both the best reference MSD ph-AFQMC and CC ΔE results within 2 kJ/mol.

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Section: Computational Detailsmentioning

confidence: 98%

Section: Computational Detailsmentioning

confidence: 99%

Scalar Relativistic All-Electron and Pseudopotential Ab Initio Study of a Minimal Nitrogenase [Fe(SH)₄H]⁻ Model Employing Coupled-Cluster and Auxiliary-Field Quantum Monte Carlo Many-Body Methods

Vysotskiy,

Filippi,

Ryde

2024

J. Phys. Chem. A

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Assessment of the applicability of DFT methods to [Cp*Rh]‐catalyzed hydrogen evolution processes

Chamkin,

Chamkina

2024

J Comput Chem

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The present computational study provides a benchmark of density functional theory (DFT) methods in describing hydrogen evolution processes catalyzed by [Cp*Rh]‐containing organometallic complexes. A test set was composed of 26 elementary reactions featuring chemical transformations and bonding situations essential for the field, including the emerging concept of non‐innocent Cp* behavior. Reference values were obtained from a highly accurate 3/4 complete basis set and 6/7 complete PNO space extrapolated DLPNO‐CCSD(T) energies. The performance of lower‐level extrapolation procedures was also assessed. We considered 84 density functionals (DF) (including 13 generalized gradient approximations (GGA), nine meta‐GGAs, 33 hybrids, and 29 double‐hybrids) and three composite methods (HF‐3c, PBEh‐3c, and r2SCAN‐3c), combined with different types of dispersion corrections (D3(0), D3BJ, D4, and VV10). The most accurate approach is the PBE0‐DH‐D3BJ (MAD of 1.36 kcal mol−1) followed by TPSS0‐D3BJ (MAD of 1.60 kcal mol−1). Low‐cost r2SCAN‐3c composite provides a less accurate but much faster alternative (MAD of 2.39 kcal mol−1). The widely used Minnesota‐family M06‐L, M06, and M06‐2X DFs should be avoided (MADs of 3.70, 3.94, and 4.01 kcal mol−1, respectively).

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A larger basis set describes atomization energy core–valence correction better than a higher-order coupled-cluster method

Abstract: The accuracy of coupled-cluster methods for the computation of core-valence correction to atomization energy was assessed. Truncation levels up to CCSDTQP were considered together with (aug-)cc-pwCVnZ (n = D, T,...

Cited by 2 publications

References 64 publications

Scalar Relativistic All-Electron and Pseudopotential Ab Initio Study of a Minimal Nitrogenase [Fe(SH)₄H]⁻ Model Employing Coupled-Cluster and Auxiliary-Field Quantum Monte Carlo Many-Body Methods

Scalar Relativistic All-Electron and Pseudopotential Ab Initio Study of a Minimal Nitrogenase [Fe(SH)₄H]⁻ Model Employing Coupled-Cluster and Auxiliary-Field Quantum Monte Carlo Many-Body Methods

Assessment of the applicability of DFT methods to [Cp*Rh]‐catalyzed hydrogen evolution processes

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A larger basis set describes atomization energy core–valence correction better than a higher-order coupled-cluster method

Abstract: The accuracy of coupled-cluster methods for the computation of core-valence correction to atomization energy was assessed. Truncation levels up to CCSDTQP were considered together with (aug-)cc-pwCVnZ (n = D, T,...

Cited by 2 publications

References 64 publications

Scalar Relativistic All-Electron and Pseudopotential Ab Initio Study of a Minimal Nitrogenase [Fe(SH)4H]− Model Employing Coupled-Cluster and Auxiliary-Field Quantum Monte Carlo Many-Body Methods

Scalar Relativistic All-Electron and Pseudopotential Ab Initio Study of a Minimal Nitrogenase [Fe(SH)4H]− Model Employing Coupled-Cluster and Auxiliary-Field Quantum Monte Carlo Many-Body Methods

Assessment of the applicability of DFT methods to [Cp*Rh]‐catalyzed hydrogen evolution processes

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Scalar Relativistic All-Electron and Pseudopotential Ab Initio Study of a Minimal Nitrogenase [Fe(SH)₄H]⁻ Model Employing Coupled-Cluster and Auxiliary-Field Quantum Monte Carlo Many-Body Methods

Scalar Relativistic All-Electron and Pseudopotential Ab Initio Study of a Minimal Nitrogenase [Fe(SH)₄H]⁻ Model Employing Coupled-Cluster and Auxiliary-Field Quantum Monte Carlo Many-Body Methods