Related papers: Theoretical X-Ray Absorption Debye-Waller Factors
Of particular interest for radio and hard X-ray diagnostics of accelerated electrons during solar flares is the understanding of the basic non-linear mechanisms regulating the relaxation of electron beams propagating in turbulent plasmas.…
We develop the theory of dynamical superradiance -- the collective exchange of energy between an ensemble of initially excited emitters and a single-mode cavity -- for organic materials where electronic states are coupled to vibrational…
The optical absorbance of 2D semiconductors is generalized to individual lattice sites through the topological marker formalism, yielding an absorbance marker. This marker allows to investigate the atomic scale variation of absorbance…
This paper presents some absorbing boundary conditions (ABC) for simulations based on the time-dependent density-functional theory (TDDFT). The boundary conditions are expressed in terms of the elements of the density-matrix, and it is…
Predicting the emerging X-ray spectra in several astrophysical objects is of great importance, in particular when the observational data are compared with theoretical models. To this aim, we have developed an algorithm solving the radiative…
A method is described for using resonant x-ray scattering to separately quantify the charge (valence) modulation and the strain wave associated with a charge density wave. The essence of the method is a separation of the atomic form factor…
An acoustic reverberator consisting of a network of delay lines connected via scattering junctions is proposed. All parameters of the reverberator are derived from physical properties of the enclosure it simulates. It allows for simulation…
One of the primary science goals of the next generation of hard X-ray timing instruments is to determine the equation of state of the matter at supranuclear densities inside neutron stars, by measuring the radius of neutron stars with…
We present a time-dependent density functional theory (TDDFT) based approach to compute the light-matter couplings between two different manifolds of excited states relative to a common ground state. These quantities are the necessary…
We describes a new approach for performing quantitative structure-factor analysis and density measurements of liquids using x-ray diffraction with a pink-spectrum x-ray source. The methodology corrects for the pink beam effect by performing…
We investigate both analytically and by numerical simulation the kinetics of a microscopic model of hard rods adsorbing on a linear substrate, a model which is relevant for compaction of granular materials. The computer simulations use an…
In amorphous solids, a non-negligible part of thermal conductivity results from phonon scattering on the structural disorder. The conversion of acoustic energy into thermal energy is often measured by the Dynamical Structure Factor (DSF)…
We present the theory of dielectric spectra allowing for homogeneous and inhomogeneous broadening mechanisms contributions. The dielectric absorption line shape for oscillators with memory and Debye type relaxors with distribution of,…
Minimization of the number of numerically calculated coefficients for new analytical forms as a product of exponential function r1 by the sum of the exponential terms Ai*exp(-ai*r2) have been done. The optimum is N=10. Calculations have…
Radiation transport plays important roles in stellar atmospheres, but the effects of turbulence are being obscured by other effects such as stratification. Using radiative hydrodynamic simulations of forced turbulence, we determine the…
We report on simulations and measurements of the optical absorption of silicon nanowires (NWs) versus their diameter. We first address the simulation of the optical absorption based on two different theoretical methods : the first one,…
Atomic vibrations are usually not taken into account when analyzing x-ray absorption near edge structure (XANES) spectra. One of the reasons is that including the vibrations in a formally exact way is quite complicated while the effect of…
A new method for calculating optical absorption spectra within linear-scaling density-functional theory (LS-DFT) is presented, incorporating a scheme for optimizing a set of localized orbitals to accurately represent unoccupied Kohn-Sham…
This work theoretically analyzes the sound absorption properties of a chirped multi-layer porous material including transmission, in particular showing the broadband unidirectional absorption properties of the system. Using the combination…
Photoabsorption spectrum of the Xe@C$_{60}$ endohedral fullerene has been studied using the time-dependent-density-functional-theory (TDDFT), which represents the dynamical polarizability of an interacting electron system by an off-diagonal…