Electronic Structure of Muonated La2CuO4

2015 ◽  
Vol 827 ◽  
pp. 240-242 ◽  
Author(s):  
Ainul Fauzeeha Rozlan ◽  
Shukri Sulaiman ◽  
M.I. Mohamed-Ibrahim ◽  
Isao Watanabe
Keyword(s):  
Electronic Structure ◽  
Spin Density ◽  
Molecular Orbital ◽  
Effective Charge ◽  
The Other ◽  
Cluster Method ◽  
Computational Studies ◽  
First Principle ◽  
Apical Oxygen ◽  
Pure System

We have performed First Principle computational studies utilizing Molecular-Orbital (MO) Cluster method to examine the electronic structure of muonated La2CuO4. Based on recent works, we investigated three suggested muon sites in La2CuO4. Two possible muon sites are located near the apical oxygen O(a), and the other one is near the planar oxygen O(p). The calculations were performed at the HF/Gen level of theory. The results of our investigation show that there is a very significant covalency effect between copper and oxygen. In the pure system, the effective charge on Cu is 0.77 while the charge on the oxygens is around –1.8. In the muonated system, the charge on Cu reduces to 0.58. The spin density at Cu is 0.78 in the pure system and becomes 0.70 when muon is added. As for the muon, the charge and spin density are +0.22 and –0.0026 respectively.

scholarly journals Imido Cobalt Complexes with Imidyl Character

2021 ◽  
Author(s):  
alexander Reckziegel ◽  
Manjinder Kour ◽  
Beatrice Battistella ◽  
Stefan Mebs ◽  
Katrin Beuthert ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Spin Density ◽  
High Spin ◽  
Bond Activation ◽  
High Spin State ◽  
Cobalt Complexes ◽  
Spectroscopic Methods ◽  
Computational Studies ◽  
Ancillary Ligand ◽  
Unpaired Spin

We report on the synthesis of a variety of trigonal imido cobalt complexes [Co(NAryl)L<sub>2</sub>)<sup>–</sup>, (L = N(Dipp)SiMe<sub>3</sub>), Dipp = 2,6-diisopropylphenyl) bearing very long Co–NAryl bonds of around 1.75 Å. The electronic structure was interrogated using a variety of physical and spectroscopic methods indicating the first authenticated examples of cobalt bound imidyl species. Computational studies corroborate these findings and reveal that the high-spin state of these complexes gives rise to unpaired spin-density on the imide nitrogen and leads to its imidyl character. Obtained complexes are capable of intermolecular H atom abstraction from C–H bonds that yields the corresponding cobalt amides. Exchange of the Dipp-substituent on the imide by the smaller mesityl function (2,4,6-trimethylphenyl) effectuates the unexpected Me<sub>3</sub>Si shift from the ancillary ligand set to the imide nitrogen, followed by intramolecular C–H bond activation.<br>

PRESSURE EFFECT ON THE MgB2 ELECTRON STRUCTURE FROM FIRST PRINCIPLE CALCULATIONS

2007 ◽  
Vol 21 (16) ◽  
pp. 2793-2803
Author(s):  
LI CHEN
Keyword(s):  
Electronic Structure ◽  
Fermi Level ◽  
Density Of States ◽  
Electron Distribution ◽  
Pressure Effect ◽  
The Other ◽  
First Principle ◽  
First Principle Calculations ◽  
Bonding Property ◽  
Density Population

The electronic structure of MgB 2 with different lattice parameters, which represents the influence of pressure, has been studied from HF calculation. It has been found that the density of states at the Fermi level decreases with the decrease in lattice constant, which implies that the pressure can reduce the superconductivity of MgB 2. It was also found that more electrons are introduced from the Mg layer to the B layer with increasing pressure, resulting in the number of holes on the B layer being reduced, thus reducing superconductivity. The electron density population at different pressures clearly shows that the triangle-shaped electron distribution in the B plane, extended along the B–B bonds, indicates the typical sp2 orbitals. On the other hand, there is no covalency feature between Mg and B atoms, indicating the ionic bonding property between Mg and B layers.

scholarly journals Imido Cobalt Complexes with Imidyl Character

2021 ◽  
Author(s):  
alexander Reckziegel ◽  
Manjinder Kour ◽  
Beatrice Battistella ◽  
Stefan Mebs ◽  
Katrin Beuthert ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Spin Density ◽  
High Spin ◽  
Bond Activation ◽  
High Spin State ◽  
Cobalt Complexes ◽  
Spectroscopic Methods ◽  
Computational Studies ◽  
Ancillary Ligand ◽  
Unpaired Spin

We report on the synthesis of a variety of trigonal imido cobalt complexes [Co(NAryl)L<sub>2</sub>)<sup>–</sup>, (L = N(Dipp)SiMe<sub>3</sub>), Dipp = 2,6-diisopropylphenyl) bearing very long Co–NAryl bonds of around 1.75 Å. The electronic structure was interrogated using a variety of physical and spectroscopic methods indicating the first authenticated examples of cobalt bound imidyl species. Computational studies corroborate these findings and reveal that the high-spin state of these complexes gives rise to unpaired spin-density on the imide nitrogen and leads to its imidyl character. Obtained complexes are capable of intermolecular H atom abstraction from C–H bonds that yields the corresponding cobalt amides. Exchange of the Dipp-substituent on the imide by the smaller mesityl function (2,4,6-trimethylphenyl) effectuates the unexpected Me<sub>3</sub>Si shift from the ancillary ligand set to the imide nitrogen, followed by intramolecular C–H bond activation.<br>

Electronic structure of zinc phthalocyanine

1988 ◽  
Vol 66 (9) ◽  
pp. 2313-2324 ◽  
Author(s):  
N. El Khatib ◽  
B. Boudjema ◽  
M. Maitrot ◽  
H. Chermette ◽  
L. Porte
Keyword(s):  
Electronic Structure ◽  
Electronic Properties ◽  
Molecular Orbital ◽  
Visible Spectrum ◽  
The Other ◽  
Zinc Phthalocyanine ◽  
Similar Calculation ◽  
Model Molecule ◽  
Qualitative Structure ◽  
Semi Empirical

The electronic structure of zinc phthalocyanine is investigated through MSXα computations and XPS experiments. Reasonable argeement is found between the qualitative structure of the molecular orbital diagram and the XPS spectrum. The visible spectrum is also discussed and the calculation is compared to previous semi-empirical computations. On the other hand, it is shown that a similar calculation on the zinc tetraazaporphyrin — selected as a model molecule — cannot be used to interpret the electronic properties of the phthalocyanine.

The electronic structure of N2O4. I. σ-Electron delocalization study

1965 ◽  
Vol 18 (8) ◽  
pp. 1115 ◽  
Author(s):  
RD Brown ◽  
RD Harcourt
Keyword(s):  
Electronic Structure ◽  
Molecular Orbital ◽  
Bond Order ◽  
The Other ◽  
Electron Delocalization ◽  
Special Consideration ◽  
Bond Orders ◽  
Bond Properties ◽  
Classical Structure ◽  
Molecular Orbital Study

A detailed molecular orbital study of the σ- and π-electrons of N2O4 is described. Special consideration is given to possible types of oxygen σ-electron delocalization into antibonding NK and KO orbitals which are vacant in the classical structure. Of these, only depopulation of oxygen 2pπ-orbitals into the antibonding NN σ-orbital seems to be of overall importance for interpreting the NN and NO bond properties. The other oxygen a-electron delocalizations are small, and their contributions to the NO bond orders (although sometimes significant), appear largely to cancel. The possibility that our VESCF procedure may yield an overestimate in the magnitude of the calculated NN σ-bond-order is discussed. A distinction is made between the nature of molecular orbitals arising from combination of π-orbitals on oxygen with the antibonding NN and the antibonding NO orbitals respectively.

scholarly journals Effect of Ag Doping on the Electronic Structure and Optical Properties of ZnO(0001) Surface

2018 ◽  
Vol 142 ◽  
pp. 01008
Author(s):  
Qian Xiang ◽  
Shutao Zhao ◽  
Yanning Wu ◽  
Guangdong Liu
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Geometrical Structure ◽  
Electron Transition ◽  
Low Energy ◽  
The Other ◽  
First Principle ◽  
Ag Doping ◽  
First Principle Calculations ◽  
Doped Zno

Using first-principle calculations, the geometrical structure, the electronic and optical properties of Ag-doped ZnO(0001) surface have been investigated. We found that Ag-doped ZnO(0001) surface is more easily formed on the first layer. On the other hand, the doped surface has gradually become an equipotential body, showing obvious metallic characteristics. We found that a new peak appeared in the low energy region after Ag doping, which was mainly due to the electron transition between the two orbital levels of Ag-4d and O-2p.

The effect of ionic lattices on the electronic structures of polyatomic ions. I. The triiodide ion

1966 ◽  
Vol 19 (9) ◽  
pp. 1567 ◽  
Author(s):  
RD Brown ◽  
EK Nunn
Keyword(s):  
Electronic Structure ◽  
Molecular Orbital ◽  
Electron Energy ◽  
Electronic Structures ◽  
Valence Electron ◽  
Bond Orders ◽  
Bond Lengths ◽  
Molecular Orbital Study ◽  
Crystalline Environment ◽  
Asymmetric Stretch

A VESCF molecular-orbital study of the electronic structure of the triiodide anion in its crystalline environment in caesium triiodide and in tetraphenylarsonium triiodide reveals the effect of the lattices upon the electronic structures. The calculated total valence-electron energy as a function of the position of the central iodine nucleus provides an understanding of the observed geometries of the anion in the two crystals. The energy plot also implies that the asymmetric stretch of the triiodide is strongly anharmonic in the crystal. A satisfactory correlation exists between observed iodine : iodine bond lengths and computed bond orders.

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