The Adhesion Nature of Ag/MgO Interface: Hartree-Fock Study

1996 ◽  
Vol 458 ◽  
Author(s):  
E. Heifets ◽  
E. A. Kotomin

AbstractThe atomic and electronic structure of the Ag/MgO interface are calculated using the ab initio Hartree-Fock approach and a supercell model. The electronic density distribution is analyzed in detail for isolated and interacting slabs of a metal and MgO. The energetically most favorable adsorption position for Ag atoms is found to be above the O atoms. The binding energy is 0.20 eV (0.41 eV) for one and three Ag layers atop MgO substrate, respectively. The relevant equilibrium Ag-O distance is 2.64 Å(2.41 Å). Neither appreciable charge transfer in the interfacial region, nor considerable population of bonds between the silver layer and the insulating substrate take place. The adhesion energy arises mainly due to the electrostatic interaction of substrate atoms with a complicated charge redistribution in the metal monolayer, characterized by large quadrupole moments and electron density redistribution towards gap position in the middle of nearest Ag atoms.

2013 ◽  
Vol 10 (4) ◽  
pp. 1218-1222
Author(s):  
Baghdad Science Journal

Maximum values of one particle radial electronic density distribution has been calculated by using Hartree-Fock (HF)wave function with data published by[A. Sarsa et al. Atomic Data and Nuclear Data Tables 88 (2004) 163–202] for K and L shells for some Be-like ions. The Results confirm that there is a linear behavior restricted the increasing of maximum points of one particle radial electronic density distribution for K and L shells throughout some Be-like ions. This linear behavior can be described by using the nth term formula of arithmetic sequence, that can be used to calculate the maximum radial electronic density distribution for any ion within Be like ions for Z


2006 ◽  
Vol 15 (08) ◽  
pp. 1779-1788
Author(s):  
XIAN-RONG ZHOU ◽  
H. SAGAWA ◽  
XI-ZHEN ZHANG

In the frame of deformed Skyrme Hartree-Fock (HF) model with pairing correlations, the strong mass number dependence of quadrupole deformations in sd and pf shell nuclei with mass A =(16 ~ 56) is studied as a clear manifestation of the evolution of nuclear deformation in nuclear many-body systems. The competition between the deformation driving particle-vibration coupling and the shell structure is shown by a systematic study on the ratios of the protons to neutrons quadrupole moments in nuclei with T =| T z|=1. The mass number dependence of deformations obtained by deformed HF calculations is compared with the results of shell model and experimental data.


2007 ◽  
Vol 4 (3) ◽  
pp. 393-396
Author(s):  
Baghdad Science Journal

The aim of this work is to evaluate the one- electron expectation value from the radial electronic density function D(r1) for different wave function for the 2S state of Be atom . The wave function used were published in 1960,1974and 1993, respectavily. Using Hartree-Fock wave function as a Slater determinant has used the partitioning technique for the analysis open shell system of Be (1s22s2) state, the analyze Be atom for six-pairs electronic wave function , tow of these are for intra-shells (K,L) and the rest for inter-shells(KL) . The results are obtained numerically by using computer programs (Mathcad).


2018 ◽  
Vol 47 (46) ◽  
pp. 16492-16501 ◽  
Author(s):  
M. Oliver-Tolentino ◽  
M. González M. ◽  
H. Osiry ◽  
G. Ramos-Sánchez ◽  
I. González

This study evaluates the effect of equimolar substitution of manganese by cobalt or nickel in hexacyanoferrate open frameworks as electrode for Na-ion batteries.


1996 ◽  
Vol 74 (6) ◽  
pp. 1014-1020 ◽  
Author(s):  
Yosslen Aray ◽  
Jesús Rodríguez

Molecular orbital ab initio Hartree–Fock, post-Hartree–Fock at the MP2 and QCISD levels, and density functional theory calculations of the dipole moment, the topology of the electronic density, ρ(r), and its Laplacian, [Formula: see text], for CO and NO molecules are reported. The results obtained confirm that density functional methods provide remarkably good electronic properties and a good description of the topology of ρ(r) and [Formula: see text]. The Becke exchange functional with the correlation functional of Lee, Yang, and Parr was used to calculate the electronic density of the (100) Cu surface. Topological analysis of ρ(r) shows that the crystal graph corresponds to square pyramids between the atoms of the top of the surface and the atoms of the second layer The topological analysis of [Formula: see text] shows that the atomic graph of the Cu surface exhibits one (3,−3) local charge concentration surrounded by four (3,+1) local charge depletion points. Additionally, there is a (3,+3) local depletion in the midpoint between each of four contiguous Cu atoms corresponding to the active site for the adsorption of the (3,−3) local charge concentration on the C atom of the CO or the N atom of the NO molecule. The larger value of the [Formula: see text] at the nonbonded charge concentration on the atoms and the geometrical configuration of these critical points favor the interaction of the NO over the CO molecule with the (100) Cu surface. This result is in accord with the known reaction barriers for these molecules. Key words: density functional theory, Laplacian of the electronic density, (100) Cu surface, carbon monoxide, nitrogen monoxide, molecular graph, atomic graph.


1993 ◽  
Vol 48 (1-2) ◽  
pp. 134-136
Author(s):  
N. Sukumar ◽  
B. M. Deb ◽  
Harjinder Singh

Some consequences of the quantum fluid dynamics formulation are discussed for excited states of atoms and molecules and for time-dependent processes. It is shown that the conservation of electronic current density j(r) allows us to manufacture a gauge potential for each excited state of an atom, molecule or atom in a molecule. This potential gives rise to a tube of magnetic flux carried around by the many-electron system. In time-dependent situations, the evolution of the electronic density distribution can be followed with simple, site-dependent cellular automaton (CA) rules. The CA consists of a lattice of sites, each with a finite set of possible values, here representing finite localized elements of electronic charge and current density (since the charge density rno longer suffices to fully characterize a time-dependent system, it needs to be supplemented with information about the current density j).Our numerical results are presented elsewhere and further developmentis in progress.


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