XPS CHEMICAL SHIFTS FOR CO ADSORBED ON Ni(100): A THEORETICAL STUDY

1995 ◽  
Vol 02 (05) ◽  
pp. 563-568 ◽  
Author(s):  
L. PEDOCCHI ◽  
G. ROVIDA ◽  
N. RUSSO
Keyword(s):  
Density Functional ◽  
Chemical Shifts ◽  
Co Adsorption ◽  
Density Functional Method ◽  
Functional Method ◽  
Adsorption Sites ◽  
Metal Atoms ◽  
Structure Sensitive ◽  
Adsorption Of Co ◽  
Adsorption Geometry

Starting from the observed chemical shift of C-1s and O-1s ionization potentials (IP), reported in the literature for the adsorption of CO on Ni (100), and correlated to the different CO adsorption sites at different coverages, we have carried out a theoretical investigation, using a first-principle density-functional method, to calculate ionization energies for adsorbed CO in the atop and bridge sites. In our approach, the Ni (100) surface was simulated with clusters of up to nine metal atoms of different geometry, in order to test the two adsorption sites. For each cluster, the CO adsorption geometry was optimized and the O-1s and C-1s ionizations were calculated. The main result was that the (O-1s–C-1s) difference was very well reproduced even with clusters of modest size, thus confirming the possibility to use this value as a structure-sensitive parameter.

THEORETICAL INVESTIGATION OF O2 AND H2O CO-ADSORPTION ON CumCon(m+n=2∼7) CLUSTERS

2019 ◽  
Vol 26 (09) ◽  
pp. 1950064
Author(s):  
PEIYING HUO ◽  
XIURONG ZHANG ◽  
ZHICHENG YU ◽  
KUN GAO
Keyword(s):  
Charge Transfer ◽  
Theoretical Investigation ◽  
Density Functional ◽  
Theoretical Study ◽  
Co Adsorption ◽  
Density Functional Method ◽  
Functional Method

A theoretical study was carried out of CumCon-O2-H2O ([Formula: see text]) clusters using density functional method. The results indicate that O2 and H2O molecules are adsorbed at top sites. The presence of H2O promotes more charge transfer to anti-bonding orbitals of O2 molecules which can lead to the elongation of O–O bond. And the effect of charge transfer suggests the occurrence of chemisorption. Comparison between CumCon-O2 and CumCon-O2-H2O, PDOS are also discussed.

scholarly journals Metal–Metal and Metal–Ligand Bonding in Trinuclear Vinylidene Rhenium-Iron-Platinum Complex Studied by Topological Analysis of Electron Density

2020 ◽  
pp. 553-564
Author(s):  
Aleksey M. Shor ◽  
Svetlana S. Laletina ◽  
Anatoly I. Rubaylo ◽  
Elena A. Ivanova-Shor
Keyword(s):  
Electron Density ◽  
Density Functional ◽  
Topological Analysis ◽  
Density Functional Method ◽  
Platinum Complex ◽  
Functional Method ◽  
Iron Platinum ◽  
Metal Atoms ◽  
Metal Metal ◽  
Metal Ligand

Metal–metal and metal–ligand bonding in vinylidene ReFePt complex was studied by density functional method and topological analysis of electron density. Topological analysis did not found direct bonding between the metal atoms pointing to indirect metal–metal interaction mediated via the bridging vinylidene ligand. At the same time, the delocalization index δ(Fe,Pt) reveals the strong Fe–Pt interaction that allows for supposing a chemical bonding between these atoms

Excavatolides N - T, New Briaran Diterpenes from the Western Australian Gorgonian Briareum excavatum

1999 ◽  
Vol 52 (5) ◽  
pp. 359 ◽  
Author(s):  
Juliette E. Neve ◽  
Brian J. McCool ◽  
Bruce F. Bowden
Keyword(s):  
Energy Minimization ◽  
Density Functional ◽  
Chemical Shifts ◽  
Density Functional Method ◽  
Functional Method ◽  
Membered Ring ◽  
Coupling Constants ◽  
Spectroscopic Methods ◽  
Australian Sample ◽  
Western Australian

A Western Australian sample of the gorgonian Briareum excavatum, collected at Rowley Shoals, afforded one known (10) and seven new briaran diterpenes (1), (3) and (5)–(9). Gross structures and relative stereochemistries were determined by spectroscopic methods and by comparison of spectral data with those of previously reported briarans. Support for a proposed conformation of the 10-membered ring (stabilized by hydrogen-bonding) to explain atypical 1H n.m.r. chemical shifts and coupling constants in (9) was obtained from energy minimization of the proposed structure by an ab initio density functional method.

Computer Simulation of an Synthetic Ultraviolet Absorbent in the Interface of DMB and DMF

2010 ◽  
Vol 146-147 ◽  
pp. 966-971
Author(s):  
Qi Hua Jiang ◽  
Hai Dong Zhang ◽  
Bin Xiang ◽  
Hai Yun He ◽  
Ping Deng
Keyword(s):  
Computer Simulation ◽  
Computer Simulations ◽  
Density Functional ◽  
Density Functional Method ◽  
Mean Field ◽  
Functional Method ◽  
Dynamic Density ◽  
Interface Phase ◽  
Simulation Results

This work studies the aggregation of an synthetic ultraviolet absorbent, named 2-hydroxy-4-perfluoroheptanoate-benzophenone (HPFHBP), in the interface between two solvents which can not completely dissolve each other. The aggregation is studied by computer simulations based on a dynamic density functional method and mean-field interactions, which are implemented in the MesoDyn module and Blend module of Material Studios. The simulation results show that the synthetic ultraviolet absorbent diffuse to the interface phase and the concentration in the interface phase is greater than it in the solvents phase.

A New Approach for Calculating the Band Gap of Semiconductors within the Density Functional Method

2015 ◽  
Vol 242 ◽  
pp. 434-439 ◽  
Author(s):  
Vasilii E. Gusakov
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Density Functional ◽  
Density Functional Method ◽  
Functional Method ◽  
Localized States ◽  
Experimental Accuracy ◽  
Functional Theory ◽  
New Approach ◽  
The Density Functional Theory

Within the framework of the density functional theory, the method was developed to calculate the band gap of semiconductors. We have evaluated the band gap for a number of monoatomic and diatomic semiconductors (Sn, Ge, Si, SiC, GaN, C, BN, AlN). The method gives the band gap of almost experimental accuracy. An important point is the fact that the developed method can be used to calculate both localized states (energy deep levels of defects in crystal), and electronic properties of nanostructures.

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