Theory x ray absorption spectroscopy. Medical search. Frequent questions

In the high kinetic energy range of the photoelectron, the scattering cross-section with neighbor atoms is weak, and the absorption spectra are dominated by EXAFS (extended X-ray absorption fine structure), where the scattering of the ejected photoelectron of neighboring atoms can be approximated by single scattering events. (wikipedia.org)
Examples: Photoelectron spectroscopy angle integrated (XPS) and angle resolved (UPS) band mapping, "experimental" band-structure. (tuwien.ac.at)
In the studies, the methods of scanning tunneling microscopy (STM), X-ray and ultraviolet photoelectron spectroscopy (XPS, UPS) as well as near-edge X-ray absorption fine structure (NEXAFS) spectroscopy were employed. (uni-marburg.de)
Here, by using the combination of material synthesis and photoelectron spectroscopy, we demonstrate a genuine Mott transition undressed of any symmetry breaking side effects in the thin films of V2O3. (bvsalud.org)
In Chapter 4, experimental evidence for the removal of previously exposed corroded material by the alkyl-amine monolayer reagent has been provided using x-ray photoelectron spectroscopy, atomic absorption spectroscopy, and scanning electron micrography. (utexas.edu)

By means of damped coupled cluster theory at coupled cluster levels CCS, CC2, CCSD and CCSDR(3), the spectra of neon and methane have been investigated. (diva-portal.org)
Careful comparison of the experimental spectra with theory, extracts +2eV shifts in transition energies per valence hole, providing insight into correlated interactions of valence 3d with 3p and deeper-lying electrons. (stanford.edu)
The experimental spectra were compared with the predictions of the ab initio full multiple scattering theory (FEFF 8.4 code). (science24.com)
UV-visible absorption spectra display new peaks that correspond to the readily observed color change from red/orange to green upon reduction of 1 to 2. (ku.edu)
In this work, we leverage computed X-ray absorption near-edge structure (XANES) spectra of more than 10,000 inorganic materials to train a neural network (NN) classifier that predicts topological class directly from XANES signatures, achieving F$_1$ scores of 89% and 93% for topological and trivial classes, respectively. (arxiv.org)
The K-pre-edge spectra are interpreted with the aid of time-dependent d. functional theory (TD-DFT). (univ-grenoble-alpes.fr)
In order to confirm this interpretation, we used density functional theory with a Hubbard-U correction approach to compute X-ray absorption spectra of model compounds, which agree well with the experimental spectra. (stanford.edu)
The spectra of x-ray absorption spectroscopy (XAS) and RIXS are then calculated using Krylov subspace techniques. (mendeley.com)
Finally, he is working on the implementation of efficient linear response equations to compute absorption and emission spectra, both at the UV-visible and X-ray energy ranges. (lu.se)
His current focus is the simulation of X-ray absorption spectra of these systems and especially how the coupling between the two (or more) metals affect the spectral signatures. (lu.se)

We present three schemes to go beyond the electric-dipole approximation in x-ray absorption spectroscopy calculations within a four-component relativistic framework. (nhlist-lab.com)
Presented here is a framework to reduce Ir loading by combining core-shell iridium/metal nitride morphologies using in situ experiments and density functional theory (DFT) calculations. (osti.gov)
T N 200 K) within which Kondo-hybridization gradually develops below T coh 80 K. Our dynamical mean-field theory calculations indicate the antiferromagnetism and Kondo-lattice to reside predominantly on different (spin-orbit coupled) f-orbitals, offering new perception into how these two phenomena coexist in heavy heavy fermions. (nist.gov)
The observed topography of the graphene/Fe superstructure is well reproduced by density functional theory calculations, and found to result from a unique combination of the lattice mismatch and strong interfacial interaction, as probed by core-level photoemission and x-ray absorption spectroscopy. (lu.se)
The experimental results are substantiated with insights from density functional theory (DFT) calculations. (uni-marburg.de)
We have used a combination of mercury L(III)-edge X-ray absorption spectroscopy and density functional theory calculations to investigate the chemistry of interaction of mercuric ions with each of these chelation therapy drugs. (nih.gov)
Combined electron-paramagnetic-resonance and X-ray absorption spectroscopies with first principles calculations were used to investigate the substitutional behavior of Mn ions in perovskite CaTiO3 ceramics. (nist.gov)
Density functional theory calculations provide insight to the unique defect chemistry of Mn-doped CaTiO3 compared to SrTiO3 and BaTiO3, highlighting the role of octahedral rotations which accommodate ionic size mismatch between the larger host and smaller dopant cations on the cuboctahedral sites without any significant dopant-ion displacements. (nist.gov)
The model Hamiltonian can be from a single atom, small cluster or Anderson impurity model, with model parameters from density functional theory plus Wannier90 or dynamical mean-field theory calculations. (mendeley.com)
Experimental results are also compared to density functional theory calculations, which revealed that the structure-activity relationship of the epoxy-surrounded CoNOC active structure reaches optimum (ΔG*OOH ) binding energies for high selectivity. (bvsalud.org)
In case of so called entatic state models it could be shown that a combination of high energy resolution fluorescence detected X-ray absorption near edge structure (HERFD-XANES) and various density functional theory (DFT) calculations can reveal even small geometric changes and the concomitant change of the electronic structure. (uni-paderborn.de)
Employing core-level X-ray spectroscopies, scanning tunneling microscopy, and DFT calculations, they analyzed the structure and electronic properties of honeycomb boron after its reaction with aluminum. (lu.se)

Femtosecond pump-probe spectroscopy using ultrafast optical and infrared pulses has become an essential tool to discover and understand complex electronic and structural dynamics in solvated molecular, biological, and material systems. (stanford.edu)
So, not only can we record fields, we can use them observe processes that are too fast for traditional pump-probe spectroscopy. (attoworld.de)
Extension of ARPES into the time domain via pump-probe spectroscopy allows one to access the electronic structure on an ultrafast timescale: this is advantageous as the intertwined interactions in equilibrium become separated in the time domain. (ubc.ca)

These include the x-ray and neutron diffraction results from Soper's group, nonlinear femtosecond mid-IR spectroscopy studied by Bakker, X-ray adsorption (EXAFS, XANES) measurements of D'Angelo. (cecam.org)
After the EXAFS studies by Yachandra and coworkers (17-19), three first low-resolution X-ray structures appeared 10 y ago (1-3), short distances of 2.7-2.8 Å were found in S2. (lu.se)
In another EXAFS quantum chemical studies using density functional theory (DFT) study by Dau and coworkers (20), only two short Mn-Mn dis- have played a major role for obtaining a mechanistic under- tances of 2.7 Å were suggested. (lu.se)

A second model complex, this time for the CuA center, was investigated with HERFD-XANES and valence-to-core X-ray emission spectroscopy (VtC-XES). (uni-paderborn.de)

In situ X-ray absorption fine structure measurements are used to determine the structure and stability of the core-shell catalysts under OER conditions. (osti.gov)
Resonant inelastic X-ray scattering and high-resolution X-ray absorption spectroscopy were used to identify the chemical state of a Co electrocatalyst in situ during the oxygen evolution reaction. (stanford.edu)
Results from density functional theory (DFT) demonstrate that these in situ reconstructed configurations significantly enhance the HER performance by lowering the energy barrier for water dissociation and by facilitating the adsorption/desorption of HER intermediates (H*). The competitive activity in the oxygen evolution reaction (OER) arises from the transformation of the reconstructed P-Co-O-Fe-P configurations into oxygen-bridged, high-valence CoIV-O-FeIV moieties as true active intermediates. (uzh.ch)

These include electron paramagnetic resonance (EPR), resonance Raman, FTIR, and UV/visible/near-IR absorption and natural and magnetically induced circular dichroism (CD and MCD). (uga.edu)
Operando Raman spectroscopy and X-ray absorption spectroscopy (XAS) experiments were carried out to track the dynamics of their structural reconstruction and the real catalytically active intermediates during water splitting. (uzh.ch)

High Precision X-ray Measurements 2021 conference is the second edition of the HPXM2018 workshop, held at the INFN Laboratories of Frascati in 2018. (infn.it)

The 2p3d RIXS maps contain a higher level of spectral information than the L3 X-ray absorption near edge structure (XANES). (stanford.edu)
The changes in the electronic structure of Mn, Ga and As atoms in (Ga,Mn)As layers after high temperature annealing were determined by x-ray absorption near edge spectroscopy (XANES). (science24.com)

Near Edge X-ray Absorption Fine Structure (NEXAFS) allows element and chemically sensitive imaging, while X-ray Circular Magnetic Dichroism (XMCD) allows direct, highly sensitive detection of sample magnetization. (lu.se)

Here we report the experimental realization of anultrafast two-color X-ray pump X-ray probe transient absorption experiment performed in solution. (stanford.edu)

Resonant inelastic x-ray scattering (RIXS) has become a very powerful experimental technique to probe a broad range of intrinsic elementary excitations, for example, from low energy phonons and (bi-)magnons to high energy d-d, charge-transfer and plasmon excitations in strongly correlated electronic systems. (mendeley.com)
We first give a short introduction to RIXS spectroscopy, and then we discuss the implementation details of this toolkit. (mendeley.com)

The experiment is usually performed at synchrotron radiation facilities, which provide intense and tunable X-ray beams. (wikipedia.org)

Revealing core-valence interactions in solution with femtosecond X-ray pump X-ray probe spectroscopy. (stanford.edu)

Using spectroscopic imaging with the scanning tunneling microscope, complemented by neutron scattering, x-ray absorption spectroscopy, and dynamical mean-field theory, we probe the electronic states in the antiferromagnetic USb 2 as a function of temperature. (nist.gov)
His research interests are in the application of ultrafast X ray spectroscopy and scattering techniques to investigate atomic and electronic structural dynamics in condensed matter including transition-metal complexes, molecular dynamics in solution, and electronic phase transitions in correlated electron systems. (stanford.edu)
Uncovering the 3d and 4d Electronic Interactions in Solvated Ru Complexes with 2p3d Resonant Inelastic X-ray Scattering. (stanford.edu)
I wil discuss our use of coherent X-ray scattering in the stripe and skyrmion phase to obtain speckle patterns that can be used to determine domain cascades and avalanches. (lu.se)

The most obvious means of mapping heterogeneous samples beyond x‐ray absorption contrast is through elemental analysis by x‐ray fluorescence, akin to EDX methods in electron microscopy. (wikipedia.org)
We also collaborate with other groups for Mossbauer, electron-nuclear double resonance (ENDOR), X-ray absorption and X-ray crystallography studies of proteins prepared in our laboratory. (uga.edu)
A 10fs X-ray pump pulse creates a localized excitation by removing a 1s electron from an Fe atom in solvated ferro- and ferricyanide complexes. (stanford.edu)
X-band electron paramagnetic resonance spectroscopy confirms the paramagnetic nature of 2, and reveals a narrow signal at g = 2.006, consistent with the majority of the unpaired electron density being localized on the 4,4´-NO2bpy ligand. (ku.edu)
Synchrotron X-ray absorption spectroscopy and density functional theory simulations reveal that the strong electronic correlation between metallic Co nanoparticles and the atomic Co-N4 sites in the Co@C-CoNC catalyst can increase the d-electron density near the Fermi level and thus effectively optimize the adsorption/desorption of intermediates in ORR/OER, resulting in an enhanced bifunctional electrocatalytic performance. (bournemouth.ac.uk)
In the study of materials, angle-resolved photoemission spectroscopy (ARPES) can uniquely access the electronic band structure, and the electron interactions encoded within. (ubc.ca)

The samples with known ratios of oxidized and unoxidized iron provided a way to check and calibrate the team's X-ray absorption spectroscopy measurements and facilitated a comparison with the materials from their experiments. (nsf.gov)

Laboratory for theoretical studies of electronic structure and spectroscopy of open-shell and electronically excited species. (usc.edu)
Therefore this work aims at elucidating these parameters with X-ray absorption and emission techniques in conjunction with various theoretical approaches. (uni-paderborn.de)

Following the ensuing Auger-Meitner cascade, the second X-ray pulse probes the Fe 1s3p transitions in resultant novel core-excited electronic states. (stanford.edu)
Theory and applications for f → d transitions can be found in Refs. (scm.com)

3p excitation energy for neon of an accuracy of 0.40 eV at a relativistic CCSDR(3) level of theory. (diva-portal.org)

application examples in x-ray powder diffraction. (uoguelph.ca)
Moreover, single crystals suitable for X-ray diffraction analysis were grown, and the structure of 1 solved with the help of Dr. Victor W. Day. (ku.edu)

We develop detectors and spectroscopy tapping into the quantum properties of the entangled photons and single photon detectors with high quantum efficiency. (lu.se)

Recently, it has been shown that the interplay between different mechanisms underlying the formation of the superconducting condensate in the hole-doped bi-layer Bi₂Sr₂CaCu₂O₈₊δcan be addressed in the time domain by means of time- and angle-resolved photoemission spectroscopy (TR-ARPES). (ubc.ca)

2013. Tetrahalide complexes of the [U(NR) 2 ] 2+ ion: synthesis, theory, and chlorine K-edge X-ray absorption spectroscopy . (ucsb.edu)

Solid-state NMR spectroscopy is a methodology widely used for investigation of molecular structure and molecular dynamics. (shinshu-u.ac.jp)
Theory-guided X-ray absorption spectroscopy at the boron K-edge reveals molecular-level distinctions between specific boron-NMDG complexes (i.e., monochelate, bischelate) and informs macroscopic transport models. (aps.org)
Twenty years later Christian Klixbüll Jorgensen and Klaus Erik Schäffer proposed the Angular Overlap Model (AOM) that is a transcription of LF theory using molecular orbitals, still using adjustable parameters. (scm.com)

There the team used high-energy X-ray beams to conduct X-ray absorption spectroscopy, a technique that can tell scientists about the structure and composition of materials based on how they absorb X-rays. (nsf.gov)
Finally, I wil briefly show our recent studies on generating soft X-ray orbital angular momentum beams that has the potential to unravel new information about quantum properties in materials. (lu.se)

At BOREAS, experiments use either the beamline XMCD vector cryomagnet or a multipurpose UHV reflectometer in combination with x-ray photons of energy on the range of 100 eV to 4000 eV (VLS-grating monochromator) and ful - polarization control (Apple II EPU). (lu.se)

A novel method by which to calculate the near edge X-rayabsorption fine structure region of the X-ray absorption spectrum has been derived and implemented. (diva-portal.org)

X-ray microscopy al ows the application of powerful spectroscopic techniques in length scales far smal er than possible with optical microcopy. (lu.se)

By use of advanced X-ray microscopy with XMCD contrast, emergent magnetic phenomena can be directly imaged and observed in real space on a scale that goes beyond the capabilities of any other technique. (lu.se)
Soft X ray transmission microscopy with circularly polarized photons tuned at specific resonant energies allows to image magnetic textures by exploiting the dichroic absorption contrast which depends on the angle of the magnetization and X-ray beam. (lu.se)
In contrast, our previous density functional theory disagreement for the fast-exchanging substrate. (lu.se)

Ray tracing simulations, graphite mosaic crystals and their applications will have a special focus. (infn.it)

Isolated 1 was characterized by several forms of spectroscopy including nuclear magnetic resonance, electronic absorption, and mass spectrometry. (ku.edu)

His theories include the Kronig-Penney model, the Coster-Kronig transition and the Kramers-Kronig relations. (academicinfluence.com)

X-ray absorption spectroscopy (XAS) is a widely-used materials characterization technique sensitive to atoms' local symmetry and chemical bonding, which are intimately linked to band topology by the theory of topological quantum chemistry (TQC). (arxiv.org)

In particular, he is currently interested in hybrid DFT and MCSCF schemes, as well as new and more efficient formulation of perturbation theory on top of a MCSCF wavefunction. (lu.se)

Starting from the very beginning of the twenty first century until nowadays, a new, non-empirical, Density Functional Theory (DFT) based Ligand Field model 1 2 was developed, called LFDFT. (scm.com)
The calculation of the CI-matrices is based on a symmetry decomposition in the full rotation group and/or on a ligand field analysis of the energies of all single determinants (micro-states) calculated according to Density Functional Theory (DFT) for frozen KS-orbitals corresponding to the averaged configuration, possibly with fractional occupations, of the p-, d- or f-orbitals. (scm.com)

Synchrotron X‐ray absorption spectroscopy and magnetic characteristics studies of metal ferrites (metal= Ni, Mn, Cu) synthesized by sol-gel auto‐combustion method. (wikipedia.org)

The essential quantum resource behind the envisioned quantum light spectroscopy is the photons' time-frequency entanglement. (lu.se)

Research in this area sets focus on the theory of quantum-optically confined systems of ultra-cold atoms and molecules and related nanostructures. (lu.se)

Results obtained at the damped coupled cluster and STEX levels of theory, respectively, are seen to be in agreement, with a mere relative energy shift. (diva-portal.org)

We focus on studies of light interacting with nanoscale systems, in both experiment and theory. (lu.se)

In accord with this theory, the singly reduced species (2) could be chemically prepared and isolated. (ku.edu)

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