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Related papers: R-Matrix calculations for opacities: I. Methodolog…

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A grid-based real-space implementation of the Projector Augmented Wave (PAW) method of P. E. Blochl [Phys. Rev. B 50, 17953 (1994)] for Density Functional Theory (DFT) calculations is presented. The use of uniform 3D real-space grids for…

Materials Science · Physics 2009-11-10 J. J. Mortensen , L. B. Hansen , K. W. Jacobsen

We describe an ab initio and non-perturbative $R$-matrix with time-dependence theory for ultrafast atomic processes in light fields of arbitrary polarization. The theory is applicable to complex, multielectron atoms and atomic ions subject…

Atomic Physics · Physics 2018-12-04 D. D. A. Clarke , G. S. J. Armstrong , A. C. Brown , H. W. van der Hart

Several different approximations and techniques have been developed for the calculation of atomic structure, ionization, and excitation of atoms and ions. These techniques have been used to compute large amounts of spectroscopic data of…

Astrophysics · Physics 2007-05-23 Manuel A. Bautista

We employ the time-dependent R-Matrix (TDRM) method to calculate anisotropy parameters for positive and negative sidebands of selected harmonics generated by two-color two-photon above threshold ionization of argon. We consider odd…

Atomic Physics · Physics 2013-10-24 Steven Hutchinson , Michael A. Lysaght , Hugo W. van der Hart

Spectral lines of heavy atomic elements in the ejecta of supernovae and neutron star mergers can have important contribution to the opacity of the ejecta matter even when the abundance of the elements is very small. Under favorable…

High Energy Astrophysical Phenomena · Physics 2019-12-13 Li-Xin Li

Raman spectroscopy is an advantageous method for studying the local structure of materials, but the interpretation of measured spectra is complicated by the presence of oblique phonons in polycrystals of polar materials. Whilst group theory…

A program RCFP will be presented for calculating standard quantities in the decomposition of many-electron matrix elements in atomic structure theory. The list of quantities wich are supported by the present program includes the…

Atomic Physics · Physics 2009-11-10 G. Gaigalas , S. Fritzsche

We develop a computational approach for calculating the optical conductivity in the augmented plane wave basis set of Wien2K and apply it for thoroughly comparing the full dipole matrix element calculation and the Peierls approximation. The…

Strongly Correlated Electrons · Physics 2012-05-25 P. Wissgott , J. Kuneš , A. Toschi , K. Held

We introduce the concept of Plasmonic Parametric Resonance (PPR) as a novel way to amplify high angular momentum plasmonic modes of nanoparticles by means of a simple uniform optical pump. In analogy with parametric resonance in dynamical…

Optics · Physics 2018-02-13 Alessandro Salandrino

We present a method for the first-principles calculation of nuclear magnetic resonance (NMR) J-coupling in extended systems using state-of-the-art ultrasoft pseudopotentials and including scalar-relativistic effects. The use of ultrasoft…

Materials Science · Physics 2014-08-12 Timothy F. G. Green , Jonathan R. Yates

We introduce and test a new and highly efficient method for treating the thermal and radiative effects influencing the energy equation in SPH simulations of star formation. The method uses the density, temperature and gravitational…

Astrophysics · Physics 2009-11-13 D. Stamatellos , A. P. Whitworth , T. Bisbas , S. Goodwin

A new model for the electrical conductivity of dense plasmas with a mixture of ion species, containing no adjustable parameters, is presented. The model takes the temperature, mass density and relative abundances of the species as input. It…

Plasma Physics · Physics 2020-04-22 C. E. Starrett , N. R. Shaffer , D. Saumon , R. Perriot , T. Nelson , L. A. Collins , C. Ticknor

Hypercomplex signal processing (HSP) offers powerful tools for analyzing and processing multidimensional signals by explicitly exploiting inter-dimensional correlations through Clifford algebra. In recent years, hypercomplex formulations of…

Signal Processing · Electrical Eng. & Systems 2026-03-02 Kumar Vijay Mishra , Henry Arguello , Brian M. Sadler

Drachmann's regularization approach is implemented for floating explicitly correlated Gaussians (fECGs) and molecular systems. Earlier applications of drachmannized relativistic corrections for molecular systems were hindered due to the…

Chemical Physics · Physics 2024-06-11 Balázs Rácsai , Dávid Ferenc , Ádám Margócsy , Edit Mátyus

The self-consistent inclusion of plasma effects in opacity calculations is a significant modeling challenge. As density increases, such effects can no longer be treated perturbatively. Building on a recently published model that addresses…

Plasma Physics · Physics 2024-10-08 C. E. Starrett , C. J. Fontes , H. B. Tran Tan , J. M. Kasper , J. R. White

Accurately modelling cold and ultracold reactive collisions occuring over deep potential wells, such as \ce{D+ + H2 -> H+ + HD}, requires the development of new theoretical and computational methodologies. One potentially useful framework…

Chemical Physics · Physics 2019-02-08 Laura K. McKemmish , Jonathan Tennyson

In accelerating and supersonic media, the interaction of photons with spectral lines can be of ultimate importance. However, fully accounting for such line forces currently can only be done by specialised codes in 1-D steady-state flows.…

Solar and Stellar Astrophysics · Physics 2022-11-16 L. G. Poniatowski , N. D. Kee , J. O. Sundqvist , F. A. Driessen , N. Moens , S. P. Owocki , K. G. Gayley , L. Decin , A. de Koter , H. Sana

Spectral decomposition of matrices is a recurring and important task in applied mathematics, physics and engineering. Many application problems require the consideration of matrices of size three with spectral decomposition over the real…

Numerical Analysis · Mathematics 2021-11-04 Michal Habera , Andreas Zilian

Reservoir Computing is a relatively recent computational framework based on a large Recurrent Neural Network with fixed weights. Many physical implementations of Reservoir Computing have been proposed to improve speed and energy efficiency.…

Emerging Technologies · Computer Science 2019-09-10 Jonathan Dong , Mushegh Rafayelyan , Florent Krzakala , Sylvain Gigan

X-ray resonant magnetic reflectivity (XRMR) is a powerful method to determine the optical, structural and magnetic depth profiles of a variety of thin films. Here, we investigate samples of different complexity all measured at the Pt L$_3$…