Related papers: X-ray absorption branching ratio in actinides: LDA…
In order to obtain a reasonably accurate and easily implemented approach to many-electron calculations, we will develop a new Density Functional Theory (DFT). Specifically, we derive an approximation to electron density, the first term of…
We devise a theory of x-ray absorption by symmetric-top molecules which are aligned by an intense optical laser. Initially, the density matrix of the system is composed of the electronic ground state of the molecules and a thermal ensemble…
We have observed the X-ray transient XTE J0421+56 in quiescence with XMM-Newton. The observed spectrum is highly unusual being dominated by an emission feature at ~6.5 keV. The spectrum can be fit using a partially covered power-law and…
Absorbing a focused, femtosecond X-ray pulse from a Free-Electron Laser (FEL) can lead to extreme electronic excitations in solids. This excitation drives changes of the electronic system over the course of the pulse duration and the…
Oscillatory structure is found in the atomic background absorption in x-ray-absorption fine structure (XAFS). This atomic-XAFS or AXAFS arises from scattering within an embedded atom, and is analogous to the Ramsauer-Townsend effect.…
We study the linear optical absorption of bulk semiconductors in the presence of a homogeneous constant (dc) electric field with an approach suitable for including excitonic effects while working with many-band models. The absorption…
Lithium-ion secondary batteries have been used in a wide variety of purposes, such as for powering mobile devices and electric vehicles, but their performance should be improved. One of the factors that limits their performance is the…
We describe a complete volume limited sample of nearby active galaxies selected by their 14-195keV luminosity, and outline its rationale for studying the mechanisms regulating gas inflow and outflow. We describe also a complementary sample…
We apply attosecond transient absorption spectroscopy (ATAS) to explore the effects of a nonzero permanent dipole on electron dynamics at the subfemtosecond scale, exemplified in the polar LiF molecule. In contrast with nonpolar systems, a…
The GaAs/GaAsN interface band offset is calculated from first principles. The electrostatic potential at the core regions of the atoms is used to estimate the interface potential and align the band structures obtained from respective bulk…
Transient absorption (TA) is the most widespread method to follow ultrafast dynamics in molecules and materials. The related method of TA anisotropy (TAA) reports on the ultrafast reorientation dynamics of transition dipole moments,…
This paper describes the data acquisition system used for data readout from a segmented detector of reactor antineutrinos with active shielding. Theoretical approach to the data acquisition is described and two possible solutions using QDCs…
We present a comprehensive computational framework for reproducing the full X-ray absorption fine structure (XAFS) through quantum-chemical simulations. The near-edge region is accurately captured using an efficient implementation of…
In this work we present a four component relativistic theoretical investigation of the trihalides of lutetium and lawrencium, LuX3, LrX3 (X= F, Cl, Br, I) respectively using density functional theory (DFT) with different density functional…
We report on high spectral resolution observations of five damped Ly-alpha absorbers. Line velocity profiles and heavy element abundances are discussed. Nitrogen is found to have abundances less than silicon in the systems toward Q…
We use the new 4 Ms exposure of the CDF-S field obtained with the Chandra X-ray satellite to investigate the properties of the faintest X-ray sources over a wide range of redshifts. We use an optimized averaging procedure to investigate the…
Ta$_{3}$N$_{5}$ is among the most intensively studied photoanode materials for solar-driven water oxidation, yet its performance often remains limited by short carrier lifetimes and defect mediated recombination. Although transient…
Simulation of spectra of x-ray absorption spectroscopy (XAS) at the L-edge is a well-established and reliable computational tool that, in combination with experimental measurements, reveals details about the local electronic structure and…
Strongly correlated materials such as transition metal oxides (TMOs) often exhibit large satellites in their x-ray photoemission (XPS) and x-ray absorption spectra (XAS). These satellites arise from localized charge-transfer (CT)…
Collecting and analysing X-ray photons over either spatial or temporal scales encompassing varying optical depth values requires knowledge about the optical depth distribution. In the case of sufficiently broad optical depth distribution,…