Calculations of photoelectron spectra for tetrahedral oxyanions by the Hartree—Fock—Slater model

The Gelius intensity model has been adapted in the semiempirical HAM/3 method to calculate the valence ionization energies and intensities in XPS. Both semiempirical and àb initio Hartree–Fock–Slater atomic photoionization cross-sections can be used. Results presented for C2H2, C2H4, N2, H2O, CH3OH, and CH2F2 demonstrate that the present method can facilitate the interpretation of experimental XPS.

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Measurements of Chemical Shifts in the Photoelectron Spectra of Arsenic and Bromine Compounds

Applied Spectroscopy ◽

10.1366/000370271774371001 ◽

1971 ◽

Vol 25 (1) ◽

pp. 33-36 ◽

Cited By ~ 23

Author(s):

L. D. Hulett ◽

T. A. Carlson

Keyword(s):

Photoelectron Spectroscopy ◽

Chemical Shifts ◽

Binding Energies ◽

Photoelectron Spectra ◽

Ionic Character ◽

X Rays ◽

Arsenic Pollution ◽

Oxidation Number ◽

Hartree Fock ◽

D Orbitals

Chemical shifts in the binding energies of electrons in 3 d orbitals of bromine and arsenic have been measured by photoelectron spectroscopy, using soft x rays. The bromine salts studied were KBr, KBrO3, and KBrO4; the results are compared to corresponding chlorine and iodine salts studied by other workers. For a given increase in oxidation number, the shift (increase) in binding energy of bromine is intermediate to those for chlorine and iodine, chlorine shifts are higher, and iodine shifts are lower. This trend can be qualitatively explained by Hartree-Fock calculations of differences in binding energies for free halogen ions. Chemical shifts for arsenic can be correlated to variations in the effective charges on arsenic caused by different chemical environments. Calculations of the charge were made by considering the partial ionic character of bonds. A demonstration that photoelectron spectroscopy can be used in arsenic pollution problems has been made.

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Frontier orbitals and quasiparticle energy levels in ionic liquids

npj Computational Materials ◽

10.1038/s41524-020-00413-4 ◽

2020 ◽

Vol 6 (1) ◽

Author(s):

Juhan Matthias Kahk ◽

Ivar Kuusik ◽

Vambola Kisand ◽

Kevin R. J. Lovelock ◽

Johannes Lischner

Keyword(s):

Ionic Liquids ◽

Density Functional ◽

Energy Levels ◽

Ion Pairs ◽

Mean Field ◽

Photoelectron Spectra ◽

Gw Approximation ◽

Hartree Fock ◽

Many Body Perturbation Theory ◽

Quasiparticle Energy

Abstract Ionic liquids play an important role in many technological applications and a detailed understanding of their frontier molecular orbitals is required to optimize interfacial barriers, reactivity and stability with respect to electron injection and removal. In this work, we calculate quasiparticle energy levels of ionic liquids using first-principles many-body perturbation theory within the GW approximation and compare our results to various mean-field approaches, including semilocal and hybrid density-functional theory and Hartree–Fock. We find that the mean-field results depend qualitatively and quantitatively on the treatment of exchange–correlation effects, while GW calculations produce results that are in excellent agreement with experimental photoelectron spectra of gas phase ion pairs and ionic liquids. These results establish the GW approach as a valuable tool for understanding the electronic structures of ionic liquids.

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A reassignment of the gas-phase photoelectron spectra of the actinide tetrahalides UF4, UCl4, ThF4 and ThCl4 by relativistic hartree-fock-slater calculations

Journal of Electron Spectroscopy and Related Phenomena ◽

10.1016/0368-2048(88)80004-5 ◽

1988 ◽

Vol 46 (1) ◽

pp. 43-53 ◽

Cited By ~ 18

Author(s):

P.M. Boerrigter ◽

J.G. Snijders ◽

J.M. Dyke

Keyword(s):

Gas Phase ◽

Photoelectron Spectra ◽

Hartree Fock

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Atomic and Electronic Structure of the Corundum (0001) Surface

MRS Proceedings ◽

10.1557/proc-453-721 ◽

1996 ◽

Vol 453 ◽

Cited By ~ 2

Author(s):

V. E. Puchin ◽

E. A. Kotomin ◽

A. L. Shluger

Keyword(s):

Electronic Structure ◽

Ab Initio ◽

Basal Plane ◽

Strong Dependence ◽

Photoelectron Spectra ◽

Slab Model ◽

Hartree Fock ◽

Electron Spectra ◽

Densities Of States ◽

Atomic And Electronic Structure

AbstractThe electronic structure and geometry of the Al terminated corundum (0001) surface were studied using a slab model within the ab-initio Hartree-Fock technique. The distance between the top Al plane and the next O basal plane is found to be considerably reduced on relaxation (by 0.57 Å, i.e. by 68% of the corresponding interlayer distance in the bulk). An interpretation of experimental photoelectron spectra (UPS Hel) and metastable impact electron spectra (MIES) is given. Calculated projected densities of states exhibit a strong dependence on the relaxation of surface atoms.

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