Roles of lateral interactions between adatoms and local surface geometry in determining the binding energies of core electrons in adsorbed species

1975 ◽  
Vol 60 ◽  
pp. 201 ◽  
Author(s):  
C. M. Quinn ◽  
N. V. Richardson
Keyword(s):  
Binding Energies ◽  
Lateral Interactions ◽  
Local Surface ◽  
Surface Geometry ◽  
Adsorbed Species ◽  
Core Electrons

DENSITY FUNCTIONAL THEORY STUDY OF THE PHOTOELECTRON SPECTRA OF 5-METHYLTETRAZOLE

2013 ◽  
Vol 12 (01) ◽  
pp. 1250096 ◽  
Author(s):  
DELANO P. CHONG
Keyword(s):  
Density Functional ◽  
Slight Modification ◽  
Binding Energies ◽  
Photoelectron Spectra ◽  
Core Electron ◽  
Functional Theory ◽  
Electron Ionization Spectrum ◽  
Core Electrons ◽  
Vertical Ionization Energies ◽  
Electron Binding Energies

The molecule 5-methyltetrazole (5MTZ) can exist in two taumeric forms. The vertical ionization energies (VIEs) of both valence and core electrons of both the tautomers are calculated with our established DFT procedures and compared with available experimental data. For the 2H-tautomer, the average absolute deviations (AADs) for the outer-valence VIEs and core-electron binding energies (CEBEs) from experiment are below 0.1 eV, while the AAD for the inner-valence VIEs is much larger at 0.4 eV. For the 1H-tautomer, no observed valence VIEs have been reported and the AAD for the calculated CEBEs is 0.2 eV. The assignment of the experimental core-electron ionization spectrum is confirmed, but our results suggest a slight modification of the assignment of the UV photoelectron spectrum of the 2H-tautomer.

Exploration of local surface geometry with minimum number of contact points and surface normal information

2012 ◽  
Vol 10 (2) ◽  
pp. 383-395 ◽  
Author(s):  
Tri Cong Phung ◽  
Min Jeong Kim ◽  
Hyungpil Moon ◽  
Ja Choon Koo ◽  
Hyouk Ryeol Choi
Keyword(s):  
Local Surface ◽  
Surface Geometry ◽  
Contact Points ◽  
Surface Normal ◽  
Minimum Number

Arsenopyrite: a spectroscopic investigation of altered surfaces

1989 ◽  
Vol 53 (370) ◽  
pp. 223-229 ◽  
Author(s):  
S. Richardson ◽  
D. J. Vaughan
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ammonium Hydroxide ◽  
Binding Energies ◽  
Spectroscopic Techniques ◽  
Xps Spectra ◽  
Natural Systems ◽  
Surface Alteration ◽  
Core Electrons ◽  
Ph Conditions ◽  
Iron Sulphates

AbstractSurfaces of a natural sample of arsenopyrite (FeAsS) were oxidized by a range of inorganic oxidants, and the resultant surface alteration products studied using various spectroscopic techniques. The oxidants used were air during heating to relatively low temperatures (150°C), steam, ammonium hydroxide, hydrogen peroxide, and sulphuric acid. Electrochemical oxidation in water was also undertaken. X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and spectral reflectance measurements, were used to characterize the surface compositions. New data are proposed for the binding energies of core electrons in arsenopyrite based on the fitted XPS spectra: 706.9 eV for the Fe 2p3/2 level, 161.2 eV for the S 2p level, and 40.7eV for the As 3d level. Spectroscopic analyses of the surfaces following oxidation indicated a range of iron oxides and hydroxides (Fe1−xO, Fe3O4, Fe2O3, FeOOH and Fe(OH)3), arsenic oxides (As2O3 and As2O5), sulphur and iron sulphates (FeSO4, Fe2(SO4)3). The relative proportions of the different phases present in the surface layer are related to the strength of the oxidant employed and, where relevant, the Eh/pH conditions prevalent during oxidation. The conclusions regarding the nature of the oxidation of arsenopyrite are discussed in relation to arsenopyrite extraction by flotation and leaching, and the breakdown of arsenopyrite in natural systems.

A comparison of local surface geometry estimation methods

1997 ◽  
Vol 10 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Alan M. McIvor ◽  
Robert J. Valkenburg
Keyword(s):  
Estimation Methods ◽  
Local Surface ◽  
Surface Geometry ◽  
Geometry Estimation

A kinetic and surface study of the oxidation of ethane by nitrous oxide and by oxygen over manganese(III) oxide

1982 ◽  
Vol 60 (7) ◽  
pp. 893-897 ◽  
Author(s):  
Craig Fairbridge ◽  
Robert Anderson Ross
Keyword(s):  
Nitrous Oxide ◽  
Infrared Spectroscopy ◽  
Catalyst Surface ◽  
Binding Energies ◽  
Adsorbed Species ◽  
X Ray ◽  
Chemisorbed Oxygen ◽  
Kinetics Of ◽  
Rate Controlling Step ◽  
Oxygen Complexes

The kinetics of the nitrous oxide/ethane and oxygen/ethane reactions on manganese(III) oxide have been studied from 573 to 673 K and from 523 to 593 K, respectively. The apparent activation energy for carbon dioxide formation was 130 ± 4 kJ mol−1 in both reactions while that for nitrogen formation in the nitrous oxide/ethane reaction changed from 106 ± 4 kJ mol−1, 573–613 K, to 133 ± 4 kJ mol−, 623–673 K. The kinetic results for both reactions fit the same rate equation:[Formula: see text]where px represents either [Formula: see text]. The rate-controlling step has been associated with the interaction of adsorbed species on the catalyst surface while both ethane and the oxidising gas appear to be directly involved in further steps in the mechanism. Samples were analysed routinely by scanning electron microscopy, X-ray powder diffraction, and infrared spectroscopy. Electron spectroscopy results from samples treated in various ways with hydrocarbon/oxidant mixtures gave O(1s) values from 528.7 to 529.7 eV which are indicative of binding energies usually associated with chemisorbed oxygen. No N(1s) spectrum was obtained from catalysts exposed to hydrocarbon/nitrous oxide mixtures, in agreement with the absence of bands in the infrared which are usually associated with nitrates or nitrogen/oxygen complexes. A binding energy value of 406.5 eV was measured in the comparable N(1s) spectrum of a catalyst used at 623 K for the oxidation of ethane by nitric oxide — a result which confirms conclusions from previous surface studies on the same system using infrared spectroscopy.

scholarly journals Changes in the local surface geometry with conserved adsorbate coverage and long-range order caused by annealing

1992 ◽  
Vol 46 (19) ◽  
pp. 12784-12787 ◽  
Author(s):  
J. N. Andersen ◽  
E. Lundgren ◽  
R. Nyholm ◽  
M. Qvarford
Keyword(s):  
Long Range ◽  
Range Order ◽  
Long Range Order ◽  
Local Surface ◽  
Surface Geometry

X-Ray Photoelectron Spectra of Aluminum Oxides: Structural Effects on the “Chemical Shift”

1973 ◽  
Vol 27 (1) ◽  
pp. 1-5 ◽  
Author(s):  
James R. Lindsay ◽  
Harry J. Rose ◽  
William E. Swartz ◽  
Plato H. Watts ◽  
Kenneth A. Rayburn
Keyword(s):  
Hydrogen Bonding ◽  
Binding Energy ◽  
Binding Energies ◽  
Photoelectron Spectra ◽  
Electrostatic Model ◽  
Structural Effects ◽  
Aluminum Oxides ◽  
X Ray ◽  
Structural Differences ◽  
Core Electrons

The aluminum (2p) electron spectra of several anhydrous and “hydrous” aluminum oxides have been recorded, and the binding energies have been measured. A simple electrostatic model is employed to explain the observed shift in binding energy and relate it to differences in structure and hydrogen bonding. Two conclusions can be drawn: structural differences must be considered when interpreting photoelectron spectra for inorganic crystalline substances; and hydrogen bonding with anions may have a measurable effect on the binding energy of core electrons of the cations.

Shape from specularities: computation and psychophysics

1991 ◽  
Vol 331 (1260) ◽  
pp. 237-252 ◽  
Keyword(s):  
Mathematical Modelling ◽  
Computational Models ◽  
3D Structure ◽  
Natural Scenes ◽  
Local Surface ◽  
Surface Geometry ◽  
Geometric Information ◽  
Visual Processes ◽  
Scene Structure ◽  
The Brain

Images of artificial and natural scenes typically contain many ‘specularities’ generated by mirror-like reflection from glossy surfaces. Until fairly recently computational models of visual processes have tended to regard specularities as obscuring underlying scene structure. Mathematical modelling shows that, on the contrary, they are rich in local geometric information. Recent psychophysical findings support the notion that the brain can apply that information. Our results concern the inference of 3D structure from 2D shaded images of glossy surfaces. Stereoscopically viewed highlights or ‘specularities’ are found to serve as cues for 3D local surface-geometry.

Computational study of the structures and photoelectron spectra of 12 azabenzenes

2019 ◽  
Vol 97 (10) ◽  
pp. 697-703 ◽  
Author(s):  
Delano P. Chong
Keyword(s):  
Computational Study ◽  
Binding Energies ◽  
Molecular Structures ◽  
Photoelectron Spectra ◽  
Basis Set ◽  
Integer Number ◽  
Core Electron ◽  
Core Electrons ◽  
Predicted Values ◽  
Vertical Ionization Energies

The molecular structures of 12 azabenzenes have been optimized with the Gaussian09 package at the level of coupled cluster singles and doubles with the basis set cc-pVTZ. The optimized geometry of each is used in the ADF13 program for the calculation of the vertical ionization energies of all the electrons. For both outer-shell and inner-shell valence electrons, the 2009 method of ΔPBE0(SAOP) is used, whereas the 1999 method of ΔPW86PW91 + Crel is employed for the core electrons. For degenerate orbitals, the alternative method chosen is to use localized orbitals, keeping the integer number of electrons, while giving up proper symmetry, rather than to keep symmetry with fractional electrons. The success of the computed results of valence ionization potentials of pyridine and the diazabenzenes gives confidence for the predicted values for the higher azabenzenes. The calculated results for core-electron binding energies provide incentive to experimentalists to measure them with X-ray photoelectron spectrometers and (or) synchrotron facilities.

Accounting for the local surface geometry in the classical theory of spin waves

2011 ◽  
Vol 66 (5) ◽  
pp. 416-421 ◽  
Author(s):  
A. K. Nukhov ◽  
G. M. Musaev ◽  
K. K. Kazbekov
Keyword(s):  
Classical Theory ◽  
Spin Waves ◽  
Local Surface ◽  
Surface Geometry
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