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Atomic data for opacity calculations. II. Computational methods
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TLDR
A detailed description of the methods being used in a collaborative effort which is referred to as the Opacity Project is given in this article, where the close-coupling approximation of electron-atom collision theory is used to calculate energies and wavefunctions for bound states, oscillator strengths, photoionisation cross sections and parameters for line broadening by electron impact.Abstract:
For pt.I see ibid., vol.20, p.6363-78 (1987). A general description of the data requirements for opacity calculations has been given in paper I. The present paper gives a detailed description of the methods being used in a collaborative effort which is referred to as the Opacity Project. The close-coupling approximation of electron-atom collision theory is used to calculate energies and wavefunctions for bound states, oscillator strengths, photoionisation cross sections and parameters for line broadening by electron impact. The computations are made using the R-matrix method together with new codes for calculating outer-region solutions and dipole integrals. Use of these techniques provides an efficient means of calculating large amounts of accurate atomic data.read more
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References
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Journal ArticleDOI
Quantum defect theory
TL;DR: Quantum defect theory (QDT) as mentioned in this paper is a unified theory of bound states, including series perturbations, autoionisation and electron-ion scattering, both elastic and inelastic.
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Techniques for the calculation of atomic structures and radiative data including relativistic corrections
TL;DR: Superstructure as mentioned in this paper is a general-purpose automatic atomic-structure program that uses multi-configuration type expansions to calculate term energies, intermediate-coupling energy levels, term coupling coefficients, and cascade coefficients.
Journal ArticleDOI
Atomic data for opacity calculations. I. General description
TL;DR: In this paper, the authors give some of the formulae from thermodynamics and atomic physics which are required for opacity calculations, which are used to obtain improved values for opacities in stellar envelopes.
Journal ArticleDOI
Electron scattering by complex atoms
TL;DR: In this paper, a theory of electron scattering by complex atoms is developed in which the target atomic eigenstates and pseudostates are written as linear sums of configurations and the incident electron wave function is expanded in terms of orbitals which satisfy logarithmic boundary conditions on the surface of a sphere.
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On a screening theory of atomic spectra
TL;DR: In this article, a theoretical scheme for describing atomic spectra is developed, which differs from the current one in three main ways: (i) the nuclear charge Z enters explicitly into all predictions made with the new scheme, and (ii) certain effects of configuration interaction are allowed for in the first approximation.