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Related papers: Atomic data and spectral model for Fe III

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In a recent paper, Mohan et al. [Can. J. Phys. {\bf 95} (2017) 173] have reported results for collision strengths ($\Omega$) and effective collision strengths ($\Upsilon$) for transitions from the ground to higher 51 excited levels of…

Atomic Physics · Physics 2018-05-24 K M Aggarwal

The previously developed technique for evaluation of charge-transfer and electron-excitation processes in low-energy heavy-ion collisions [I.I. Tupitsyn et al., Phys. Rev. A 82, 042701(2010)] is extended to collisions of ions with neutral…

State-of-the-art NLTE model-atmosphere codes have arrived at a high level of numerical sophistication and are now useful tools to analyze high-quality spectra from the infrared to the X-ray wavelength range. The capacity of current…

Astrophysics · Physics 2007-05-23 Thomas Rauch , Jochen L. Deetjen

In this chapter we focus first on the theoretical methods and relevant computational approaches to calculate the electronic structure of atoms, molecules, and clusters containing heavy elements for which relativistic effects become…

Chemical Physics · Physics 2021-10-05 Simone Taioli , Stefano Simonucci

There are major discrepancies between recent ICFT (Intermediate Coupling Frame Transformation) and DARC (Dirac Atomic R-matrix Code) calculations (Fern\'andez-Menchero et al. 2014, Astron. Astroph. 566 A104, Aggarwal et al. 2016 Mon. Not. R…

Atomic Physics · Physics 2017-03-10 L. Fernández-Menchero , O. Zatsarinny , K. Bartschat

Core-level spectra of 1s electrons of elements heavier than Ne show significant relativistic effects. We combine advances in orbital optimized DFT (OO-DFT) with the spin-free exact two-component (X2C) model for scalar relativistic effects,…

Chemical Physics · Physics 2022-04-19 Leonardo A. Cunha , Diptarka Hait , Richard Kang , Yuezhi Mao , Martin Head-Gordon

There has been a growing request from the X-ray astronomy community for a quantitative estimate of systematic uncertainties originating from the atomic data used in plasma codes. Though there have been several studies looking into atomic…

Relativistic energy shifts of the low energy levels of Fe have been calculated using the Dirac-Hartree-Fock and configuration interaction techniques. The results are to be used in the search for the space-time variation of the fine…

Atomic Physics · Physics 2009-11-13 V. A. Dzuba , V. V. Flambaum

The calculation of accurate collision strengths for atomic transitions has been a long standing problem in quantitative spectroscopy. Most modern calculations are based on the R-matrix method and problems pertaining to the use of this…

Astrophysics · Physics 2007-05-23 P. A. M. van Hoof , D. A. Beintema , D. A. Verner , G. J. Ferland

Modelling of massive stars and supernovae (SNe) plays a crucial role in understanding galaxies. From this modelling we can derive fundamental constraints on stellar evolution, mass-loss processes, mixing, and the products of…

Atomic Physics · Physics 2016-09-07 N. B. Tyndall , C. A. Ramsbottom , C. P. Ballance , A. Hibbert

Results for energy levels, radiative rates and electron impact excitation (effective) collision strengths for transitions in Be-like Cl XIV, K XVI and Ge XXIX are reported. For the calculations of energy levels and radiative rates the…

Solar and Stellar Astrophysics · Physics 2015-06-22 K. M. Aggarwal , F. P. Keenan

We report calculations of energy levels, radiative rates and electron impact excitation cross sections and rates for transitions in Be-like Ti XIX. The GRASP (General-purpose Relativistic Atomic Structure Package) is adopted for calculating…

Atomic Physics · Physics 2015-06-11 Km Aggarwal , Fp Keenan

Recent advances in theoretical atomic physics have enabled large-scale calculation of atomic parameters for a variety of atomic processes with high degree of precision. The development and application of these methods is the aim of the Iron…

Astrophysics · Physics 2007-05-23 Anil K. Pradhan

A new method for solving the time-dependent two-center Dirac equation is developed. The time-dependent Dirac wave function is represented as a sum of atomic-like Dirac-Sturm orbitals, localized at the ions. The atomic orbitals are obtained…

The growing interest in atomic structures of moderately-stripped alkali-like ions in diagnostic study and modeling of astrophysical and laboratory plasma makes an accurate many-body study of atomic properties inevitable. This work presents…

Atomic Physics · Physics 2023-03-30 Swapan Biswas , Anal Bhowmik , Arghya Das , Radha Raman Pal , Sonjoy Majumder

Large-scale self-consistent multiconfiguration Dirac--Hartree--Fock and relativistic configuration interaction calculations are reported for the $n \leq 6$ levels in Be-like ions from B II to Ne VII. Effects from electron correlation are…

The spectra of singly ionised Strontium and Yttrium (Sr {\sc ii} and Y {\sc ii}) have been proposed as identifications of certain spectral features in the AT2017gfo spectrum. With the growing demand for NLTE simulations of Kilonovae, there…

High Energy Astrophysical Phenomena · Physics 2024-07-02 Leo Mulholland , Niall McElroy , Fiona McNeill , Stuart Sim , Connor Ballance , Catherine Ramsbottom

Spectral modelling of kilonovae (KNe) require large amounts of collisional excitation and photoionization atomic data for lowly ionised (neutral, singly and doubly ionised) species of heavy elements. Much of the data currently used is…

High Energy Astrophysical Phenomena · Physics 2026-02-25 Leo P. Mulholland , Catherine A. Ramsbottom , Connor P. Ballance , Albert Sneppen , Stuart A. Sim

Energy levels, radiative rates and lifetimes are calculated among the lowest 98 levels of the n <= 4 configurations of Be-like Al X. The GRASP (General-purpose Relativistic Atomic Structure Package) is adopted and data are provided for all…

Solar and Stellar Astrophysics · Physics 2015-06-18 K. M. Aggarwal , F. P. Keenan

There have been discussions in the recent literature regarding the accuracy of the available electron impact excitation rates (equivalently effective collision strengths $\Upsilon$) for transitions in Be-like ions. In the present paper we…

Atomic Physics · Physics 2016-09-07 K. M. Aggarwal , F. P. Keenan , K. D. Lawson