Static electric dipole polarizabilities for isoelectronic sequences

Koch, Volker; Andrae, Dirk

doi:10.1002/qua.22911

Cited by 11 publications

(15 citation statements)

References 46 publications

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“…Various density functionals have been shown to outperform HF for molecular static dipole polarizabilities with hybrid functionals yielding the best results, [26][27][28][29][30] as the error in polarizabilities typically arises from the exchange part. 30 Fully numerical all-electron HF results for atoms [31][32][33][34] and density functional results for molecules 35 have been reported in the literature, whereas post-HF and relativistic DFT results have been calculated using Gaussian basis sets. [36][37][38][39][40] In our application, we study the Li + and Sr 2+ ions with HF and show that we are able to reproduce the fully numerical HF limit values from ref.…”

Section: Introductionmentioning

confidence: 99%

Fully numerical Hartree‐Fock and density functional calculations. I. Atoms

Lehtola

2019

Int J of Quantum Chemistry

162

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Although many programs have been published for fully numerical Hartree-Fock (HF) or density functional (DF) calculations on atoms, we are not aware of any programs that support hybrid DFs, which are popular within the quantum chemistry community due to their better accuracy for many applications, or that can be used toWe present two applications of the novel code. The first application is the calculation of atoms in finite electric fields. Finite electric field calculations allow, for instance, the extraction of atomic static dipole polarizabilities, which are a well-known challenge for theoretical methods [20] and the best values for which have been recently reviewed by Schwerdtfeger and Nagle. [21] Atomic static dipole polarizabilities are related to global softness and the Fukui function. [22] As the molecule with the lowest static dipole polarizability tends to be the chemically most stable, [23][24][25] the accuracy of static dipole polarizabilities can be considered a proxy for thermochemical accuracy. Various density functionals have been shown to outperform HF for molecular static dipole polarizabilities, with hybrid functionals yielding the best results, [26][27][28][29][30] as the error in polarizabilities typically arises from the exchange part. [30] Fully numerical all-electron HF results for atoms [31][32][33][34] and density functional results for molecules [35] have been reported in the literature, whereas post-HF and relativistic DFT results have been calculated using Gaussian basis sets. [36][37][38][39][40] In our application, we study the Li + and Sr 2+ ions with HF and show that we are able to reproduce the fully numerical HF limit values from Ref. [41]. In addition, we report dipole moments and polarizabilities with the LDA, [42][43][44] PBE, [45,46] PBEh, [47,48] TPSS, [49,50] and TPSSh [51] functionals.Our second application is the benchmark of Gaussian basis set energies for a variety of neutral, cationic, and anionic species with HF and the BHHLYP [10] functional. Atomic anions are especially challenging to model with DFT. [52][53][54][55][56] For instance, it has been shown that calculations on the well-bound F − anion may require extremely diffuse basis functions with exponents as small as (!) α = 6.9 × 10 −9 to achieve converged results. [54] The use of such small exponents requires extensive modifications to the used Gaussian-basis quantum chemistry program to ensure sufficient numerical accuracy. [54,56] In contrast, the finite element method (FEM) has none of these issues: because the basis set has local support and is never ill-conditioned, calculations are extremely stable numerically. We will show below that the absolute energies reproduced by the large Gaussian basis set used in Refs. [56,57] are too large by several microhartrees for most systems. The second part of the present series [58] presents analogous applications to diatomic molecules, where the deficiencies of Gaussian basis sets are considerably more noticeable. [6,58] The layout of the article is the following. Next,...

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Section: Introductionmentioning

confidence: 99%

Fully numerical Hartree‐Fock and density functional calculations. I. Atoms

Lehtola

2019

Int J of Quantum Chemistry

162

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“…values found by Safronova et al (2014) who used the first and the second-order relativistic many-body perturbation theory (2.089 and 2.062 a 0 3 , respectively), with the value from Koch & Andrae (2011), 2.176 a 0 3 , and with the semiempirical value from Reshetnikov et al (2008), 2.00 a 0 3 . For all other level groups, no straight lines could be fitted that were at least close to the estimated energy level uncertainty.…”

Section: Discussionmentioning

confidence: 91%

Revised and Extended Analysis of Ar vi

Pagan

Raineri

Gallardo

et al. 2023

ApJS

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This paper analyzes the emission spectrum of Ar vi and adds new information about this ion. We use a capillary light source to study the Ar vi spectrum, presenting 39 line classifications for the first time, including one line in the ultraviolet region. A total of nine possible Ar vi lines in the ultraviolet between 3288 and 3440 Å are analyzed. We revised the wavelengths of the lines at 1284.01 and 1307.42 Å previously used to identify Ar vi in astronomical objects. The lifetimes, weighted transition rates (gA) and their estimated uncertainties, and cancellation factors are obtained using a Hartree–Fock calculation with energy parameters adjusted to fit the values of the experimental levels and modified to include core polarization effects. We analyze all the experimentally known transitions of the Ar vi spectrum, with particular attention to conflicting information. Isoelectronic sequences of energy levels and transitions, for which the trend is not a smooth curve, are analyzed. We revise previous studies where the information needed to support line classifications and level designations is incomplete.

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“…These methods demand knowledge on the polarizability andcore cut-off radius. The value of α d for Xe IV core, that is, for Xe 8+ is given by Koch [23] in 0.81130 a 0 3 and the rc value in 1.16 a 0 , defines the boundaries of the atomic core.…”

Section: Resultsmentioning

confidence: 99%

New Energy Levels and Transitions of 5s25p2 (6d+7s) Configurations in Xe IV

Almandos

Raineri

Pagan

et al. 2019

Atoms

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Three-times ionized xenon Xe IV spectrum in the 1070–6400 Å region was analyzed using a pulsed discharge light source. A set of 163 transitions was classified for the first time, and 36 new energy levels belonging to the 5s25p26d and 5s25p27s even configurations were determined. The relativistic Hartree–Fock method, including core-polarization effects, were used. In these calculations, the electrostatic parameters were optimized by a least-square procedure in order to improve the adjustment to experimental energy levels. We also present a calculation based on a relativistic multiconfigurational Dirac–Fock approach.

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Static electric dipole polarizabilities for isoelectronic sequences

Cited by 11 publications

References 46 publications

Fully numerical Hartree‐Fock and density functional calculations. I. Atoms

Fully numerical Hartree‐Fock and density functional calculations. I. Atoms

Revised and Extended Analysis of Ar vi

New Energy Levels and Transitions of 5s25p2 (6d+7s) Configurations in Xe IV

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