scholarly journals X-Ray Constrained Wave Functions

2016 ◽  
pp. 333-362 ◽  
Author(s):  
Alessandro Genoni ◽  
Benjamin Meyer
Keyword(s):  
Wave Functions ◽  
X Ray

X-ray absorption near edge structures in cobalt oxides

1996 ◽  
Vol 11 (9) ◽  
pp. 2242-2256 ◽  
Author(s):  
T. Jiang ◽  
D. E. Ellis
Keyword(s):  
Wave Functions ◽  
Site Symmetry ◽  
Local Geometry ◽  
Final State ◽  
Cluster Technique ◽  
Edge Structure ◽  
X Ray ◽  
Local Electronic Structure ◽  
Edge Features ◽  
X Ray Absorption

Theoretical studies have been made of K-edge x-ray absorption near edge structure (XANES) of Co in CoO, Co(OH)2, CoTiO3, Co3O4, and CoAl2O4. Correlations of experimental near edge features with site symmetry, local geometry, local electronic structure, i.e., atomic configuration, charge transfer, and backscattering from neighboring atomic potentials are interpreted. The self-consistent Discrete Variational Xa Method (DV-Xα) within an embedded cluster technique has been used to generate the crystal potential. A multiple scattering (MS) approach is then used to solve for the final state wave function. The ground state DV wave functions are analyzed in terms of the projected density of states, whereas the final state MS continuum wave functions are analyzed through the concept of photoelectron trapping time.

scholarly journals Studying the x- ray atomic Scattering form Factor and Nuclear Magnetic Shielding Constant for Be atom in its Excited state (1s2 2s 3s) and the Be - like ions

2015 ◽  
Vol 12 (1) ◽  
pp. 204-209
Author(s):  
Baghdad Science Journal
Keyword(s):  
Form Factor ◽  
Excited State ◽  
Computer Software ◽  
Wave Functions ◽  
Magnetic Shielding ◽  
Electron Systems ◽  
X Ray ◽  
Hartree Fock ◽  
Atomic Scattering ◽  
Nuclear Magnetic

The division partitioning technique has been used to analyze the four electron systems into six-pairs electronic wave functions for ( for the Beryllium atom in its excited state (1s2 2s 3s ) and like ions ( B+1 ,C+2 ) using Hartree-Fock wave functions . The aim of this work is to study atomic scattering form factor f(s) for and nuclear magnetic shielding constant. The results are obtained numerically by using the computer software (Mathcad).

Photon-recoil imaging: Expanding the view of nonlinear x-ray physics

Science ◽  
2020 ◽  
Vol 369 (6511) ◽  
pp. 1630-1633
Author(s):  
U. Eichmann ◽  
H. Rottke ◽  
S. Meise ◽  
J.-E. Rubensson ◽  
J. Söderström ◽  
...  
Keyword(s):  
Free Electron Laser ◽  
Signal Amplification ◽  
Pulse Propagation ◽  
Wave Functions ◽  
Single Atom ◽  
Experimental Protocol ◽  
X Ray ◽  
Photon Recoil ◽  
Fundamental Process ◽  
Electronic Wave Functions

Addressing the ultrafast coherent evolution of electronic wave functions has long been a goal of nonlinear x-ray physics. A first step toward this goal is the investigation of stimulated x-ray Raman scattering (SXRS) using intense pulses from an x-ray free-electron laser. Earlier SXRS experiments relied on signal amplification during pulse propagation through dense resonant media. By contrast, our method reveals the fundamental process in which photons from the primary radiation source directly interact with a single atom. We introduce an experimental protocol in which scattered neutral atoms rather than scattered photons are detected. We present SXRS measurements at the neon K edge and a quantitative theoretical analysis. The method should become a powerful tool in the exploration of nonlinear x-ray physics.

Coherent X-ray Scattering Factors for Various Configurations of Lanthanides and Their Positive Ions

1975 ◽  
Vol 53 (1) ◽  
pp. 93-96 ◽  
Author(s):  
Robert Benesch ◽  
K. M. S. Saxena
Keyword(s):  
Ground State ◽  
Wave Functions ◽  
X Ray ◽  
Hartree Fock ◽  
Positive Ions ◽  
X Ray Scattering ◽  
Scattering Factor ◽  
Ray Scattering

Coherent X-ray scattering factors have been computed from numerical Hartree–Fock wave functions for the neutral lanthanides and for their single-, double-, and triple-positive ions having the most commonly occurring 6sm4fn ground state configurations. For small scattering angles, the scattering factors for the ions vary among the various configurations. At large scattering angles all configurations for a given ion yield similar values for the scattering factor.

SCATTERING FACTORS FOR SOME OF THE HEAVIER ATOMS

1959 ◽  
Vol 37 (9) ◽  
pp. 967-969 ◽  
Author(s):  
Beatrice H. Worsley
Keyword(s):  
Wave Functions ◽  
Radial Wave ◽  
X Ray ◽  
University Of Toronto ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Atomic Scattering ◽  
Approximate Wave ◽  
The University

A program for calculating X-ray atomic scattering factors from the radial wave functions has been written for the IBM 650 installation at the University of Toronto. It has been applied to the results of self-consistent field calculations previously performed at this University on the FERUT computer. Results are given for Ne, V++, Kr, Ag+, and Pb+++. The results for Ne and V++ are compared with those calculated by Freeman using Allen's wave functions for Ne and Hartree's approximate wave functions for V++.

Silicon and Germanium Network Polyhedra viewed from Soft X-ray Spectroscopy

2007 ◽  
Vol 1044 ◽  
Author(s):  
Jun Tang ◽  
Takeshi Rachi ◽  
Marcos A Avila ◽  
Toshiro Takabatake ◽  
FagZhum Guo ◽  
...  
Keyword(s):  
Valence Band ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Theoretical Calculations ◽  
High Energy ◽  
Wave Functions ◽  
X Ray ◽  
Atomic Orbitals ◽  
Energy Facility ◽  
Silicon And Germanium

AbstractThe electronic states of Ba8Ga16Ge30 and Sr8Ga16Ge30 are studied by soft x-ray photoelectron spectroscopy (XPS) at a high-energy facility. In Ba8Ga16Ge30, three bands are resolved in the valence band region. Resonance experiments together with theoretical calculations show that the three band structures in the valence band are mainly constructed by the Ge/Ga 4s and 4p wave functions with little contributions of Ba 5s, 5p and 5d. The valence band of Sr8Ga16Ge30 shows a similar feature to that of Ba8Ga16Ge30. It is clearly shown that the atomic orbitals of Ba and Sr make little hybridization with the orbitals made by the framework polyhedra. This provides the understanding of the thermoelectricity in clathrates, and assists the design in high performance thermoelectric materials in this family.

The intensity of X-ray spectrum lines of heavy elements

1936 ◽  
Vol 32 (3) ◽  
pp. 461-470 ◽  
Author(s):  
H. S. W. Massey ◽  
E. H. S. Burhop
Keyword(s):  
Dipole Moment ◽  
Magnetic Dipole ◽  
Magnetic Dipole Moment ◽  
Wave Functions ◽  
Spectral Lines ◽  
Heavy Elements ◽  
Relativistic Wave ◽  
X Ray ◽  
Good Agreement

The intensities of X-ray spectral lines resulting from transitions between the K, L and M shells have been calculated using screened relativistic wave functions. The relativistic modifications are shown to decrease the Lβ3β4 doublet ratio but do not alter the Kα1α2 and Kβ1β3 ratios, in agreement with experiment. The calculated intensities of the forbidden lines arising from quadrupole transitions are in good agreement with experiment. Lines due to transitions arising from the magnetic dipole moment of the electron are found to be very weak, but the LI → K transition might just be observable for heavy elements.

scholarly journals Equation-of-Motion Coupled-Cluster Theory to Model L-edge X-Ray Absorption and Photoelectron Spectra

2020 ◽  
Author(s):  
Marta Lopez Vidal ◽  
Pavel Pokhilko ◽  
Anna Krylov ◽  
Sonia Coriani
Keyword(s):  
Small Molecules ◽  
Particle Density ◽  
Equation Of Motion ◽  
Wave Functions ◽  
Model Systems ◽  
Photoelectron Spectra ◽  
Coupled Cluster ◽  
Coupled Cluster Theory ◽  
X Ray ◽  
X Ray Absorption

We present an extension of the equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) theory for computing x-ray L-edge spectra, both in the absorption (XAS) and photoelectron (XPS) regimes. The approach is based on the perturbative evaluation of spin-orbit couplings using the Breit-Pauli Hamiltonian and nonrelativistic wave-functions described by the fc-CVS-EOM-CCSD ansatz (EOM-CCSD within the frozen-core core-valence separated (fc-CVS) scheme). The formalism is based on spinless one-particle density matrices. The approach is illustrated by modeling XAS and XPS of several model systems ranging from argon atoms to small molecules containing sulfur and silicon.

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