Core-Level 2s and 2p Binding Energies of Third-Period Elements (P, S, and Cl) Calculated by Hartree–Fock and Kohn–Sham Δ<i>S</i>CF Theory

Hirao, Kimihiko; Nakajima, Takahito; Chan, Bun

doi:10.1021/acs.jpca.3c04783

Cited by 5 publications

(3 citation statements)

References 58 publications

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“…To accurately determine the physical and chemical properties of molecules [1][2][3][4][5], an ab initio calculation of the electronic structures of molecules requires solving the Schrödinger equation for an interacting many-electron system, relying solely on atomic positions and types as inputs [6][7][8][9][10]. Hartree-Fock (HF), one of popular ab initio methods, is a mean-field approximation to minimize the energy of a wave function by identifying the dominant Slater determinant in the system wave function and optimizing the spatial form of the spin-orbitals [11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Hartree-fock roothaan calculations using optimized huzinaga orbitals on small molecules

Jaelani,

Riyanto,

Prayitno

et al. 2024

Phys. Scr.

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We present the ground-state solution of some small molecules using the Hartree-Fock Roothaan method with the optimized Huzinaga basis set. Unlike the previously used least-square methods, the contraction coefficients and exponents of Huzinaga-parameterized primitive Gaussian functions for minimal basis sets are energy-optimized at the atomic level for each molecule. Consequently, as an alternative to and in comparison with standard parameterization, the optimized orbitals significantly improve the total energy and the equilibrium bond length with substantial enhancement shown for heavier nuclei. Despite similar computational cost, the application of our scheme leads to much improved minimal-basis-set Hartree-Fock calculations with less required parameters to match the large basis set calculations. Furthermore, the localization of the electrons near the nuclei which is missing with the standard parameterization is observed with the current scheme.

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Section: Introductionmentioning

confidence: 99%

Hartree-fock roothaan calculations using optimized huzinaga orbitals on small molecules

Jaelani,

Riyanto,

Prayitno

et al. 2024

Phys. Scr.

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“…Similarly, within density-functional theory (DFT), the Kohn–Sham (KS) orbital energies can be used as approximate ionization energies. − The accurate computation of IPs within KS-DFT is still an ongoing research field with, for example, long-range corrected functionals, KS potential adjustors, , double-hybrids functionals, or even functionals directly optimized for IPs. ,− An alternative way to compute electron detachment energies at the HF or KS-DFT levels is through the state-specific self-consistent-field (ΔSCF) formalism, where one optimizes both the neutral ground state and the cationic state of interest, the IPs being computed as the difference between these two total energies. This strategy has been mainly used to compute core binding energies and is known to perform better than Koopmans’ theorem thanks to orbital relaxation. − …”

Section: Introductionmentioning

confidence: 99%

“…This strategy has been mainly used to compute core binding energies and is known to perform better than Koopmans’ theorem thanks to orbital relaxation. 52 − 58 …”

Section: Introductionmentioning

confidence: 99%

Reference Energies for Valence Ionizations and Satellite Transitions

Marie,

Loos

2024

J. Chem. Theory Comput.

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Upon ionization of an atom or a molecule, another electron (or more) can be simultaneously excited. These concurrently generated states are called “satellites” (or shakeup transitions) as they appear in ionization spectra as higher-energy peaks with weaker intensity and larger width than the main peaks associated with single-particle ionizations. Satellites, which correspond to electronically excited states of the cationic species, are notoriously challenging to model using conventional single-reference methods due to their high excitation degree compared to the neutral reference state. This work reports 42 satellite transition energies and 58 valence ionization potentials (IPs) of full configuration interaction quality computed in small molecular systems. Following the protocol developed for the quest database [Véril, M.; Scemama, A.; Caffarel, M.; Lipparini, F.; Boggio-Pasqua, M.; Jacquemin, D.; and Loos, P.-F. Wiley Interdiscip. Rev.: Comput. Mol. Sci. 2021, 11, e1517], these reference energies are computed using the configuration interaction using a perturbative selection made iteratively (CIPSI) method. In addition, the accuracy of the well-known coupled-cluster (CC) hierarchy (CC2, CCSD, CC3, CCSDT, CC4, and CCSDTQ) is gauged against these new accurate references. The performances of various approximations based on many-body Green’s functions (GW, GF2, and T-matrix) for IPs are also analyzed. Their limitations in correctly modeling satellite transitions are discussed.

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Long-range Corrected Density Functional Theory Including a Two-Gaussian Hartree−Fock Operator for High Accuracy Core-excitation Energy Calculations of Both the Second- and Third-Row Atoms (LC2gau-core-BOP)

Ahn,

Nakajima,

Hirao

et al. 2024

J. Chem. Theory Comput.

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In the previous work, LCgau-core-BOP, which includes the short-range interelectronic Gaussian attenuating Hartree−Fock (HF) exchange to the long-range HF exchange, showed high accuracy core-excitation energies from 1s orbitals of the second-row atoms (1s → π*, 1s → σ*, 1s → n*, and 1s → Rydberg), but underestimates the core-excitation energies from 1s orbitals of the third-row atoms. To improve this, we added one more Gaussian attenuating HF exchange to LCgau-core-BOP. We named it LC2gau-core-BOP, which achieves a mean absolute error (MAE) of 0.6 and 0.3 eV for core excitation energies of the second-and third-row atoms of the tested small molecules, respectively. We found that the inclusion of the short-range interelectronic HF exchange at a distance ranging from 0.2 to 0.6 a.u. contributes to the increase of performances on 1s orbital energy calculations of the second-row atoms, while the inclusion of more short-range interelectronic HF exchange at a distance ranging from 0 to 0.2 a.u. does to the increase of performance on 1s orbital energy calculations of the third-row atoms. It is notable that all of these improvements were accomplished using flexible Gaussian attenuating HF exchange inclusion. LC2gau-core-BOP shows deviations of less than 0.8 eV from experimental values for all of the core-excitation energies of the tested medium-size molecules consisting of thymine, oxazole, glycine, and dibenzothiophene sulfone. Moreover, by optimizing one parameter of the OP correlation functional, LC2gau-core-BOP provides atomization energies over the G3 test set with an accuracy comparable to that of B3LYP.

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Core-Level 2s and 2p Binding Energies of Third-Period Elements (P, S, and Cl) Calculated by Hartree–Fock and Kohn–Sham ΔSCF Theory

Cited by 5 publications

References 58 publications

Hartree-fock roothaan calculations using optimized huzinaga orbitals on small molecules

Hartree-fock roothaan calculations using optimized huzinaga orbitals on small molecules

Reference Energies for Valence Ionizations and Satellite Transitions

Long-range Corrected Density Functional Theory Including a Two-Gaussian Hartree−Fock Operator for High Accuracy Core-excitation Energy Calculations of Both the Second- and Third-Row Atoms (LC2gau-core-BOP)

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