scholarly journals Density Functional Study of Electronic and Structural Properties of Gold-Cadmium Selenide/Telluride Nanoclusters

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Shimeles T. Bulbula ◽  
Hagos W. Zeweldi
Keyword(s):  
Cadmium Selenide ◽  
Structural Properties ◽  
Cluster Size ◽  
Density Functional ◽  
Minimum Energy ◽  
Building Blocks ◽  
Basis Set ◽  
Functional Study ◽  
Energy Structure ◽  
Electronic And Structural Properties

Semiconductor nanowires are one class of building blocks that show promise for application in nanoscale electronics. Metal-semiconductor nanowire helps to improve the electrical properties or create unique ones. Electronic and structural properties of cadmium selenide/telluride connected to gold electrode clusters have been the focus of this research due to their importance in constructing fast microelectric devices. The simulations were carried out by using VASP (ViennaAb-InitioSimulation Package) which utilizes the method of density functional theory (DFT) and plane wave basis set. Optimization was performed to obtain the minimum energy structure. In this research paper the result shows that the HOMO-LUMO gaps for the minimum energy cadmium selenide/telluride connected to gold electrodes decrease as cluster size increases, whereas the binding energy shows a reverse relationship with the cluster size. However, a few clusters show special properties like AuCd2Se3and AuCd2Te3clusters.

A Density Functional Theory Study of the Isomerization of Substituted 2and#39;-hydroxychalcones to the Corresponding Flavanones

2021 ◽  
Vol 43 (1) ◽  
pp. 25-25
Author(s):  
Said Abdelqadar Said Said Abdelqadar Said ◽  
Omar A Shareef and Abdulkhalik S Alkazzaz Omar A Shareef and Abdulkhalik S Alkazzaz
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Ring Closure ◽  
Basis Set ◽  
Functional Theory ◽  
Rate Determining Step ◽  
The Density Functional Theory ◽  
Electronic And Structural Properties ◽  
Maximum Hardness Principle

The transformation of 2and#39;-hydroxychalcones to their corresponding flavanones was studied theoretically by the use of the density functional theory (DFT) with B3-LYP/ 6-311G basis set to get important information about the role of both of electronic and structural properties in this process. The obtained energies were found to be in agreement with our previous results that obtained from HPLC studies. The estimated hardness, polarizability, and electrophilicity profiles were found to obey the maximum hardness principle (MHP), minimum polarizability principle (MPP), and the minimum electrophilicity principle (MEP) respectively. Flavanone ring closure was found to be the rate-determining step.

Conformation and electronic structure of Carbidopa. A QM/MD study

2016 ◽  
Vol 15 (01) ◽  
pp. 1650002
Author(s):  
Ghader M. Sukker ◽  
Nuha Wazzan ◽  
Ashour Ahmed ◽  
Rifaat Hilal
Keyword(s):  
Density Functional ◽  
Minimum Energy ◽  
Geometry Optimization ◽  
Md Simulations ◽  
Energy Structure ◽  
Functional Theory ◽  
Conformational Preferences ◽  
The Density Functional Theory ◽  
Quantum Chemical Topology ◽  
Bonding Characteristics

Carbidopa (CD) is a drug used in combination with L-dopa (LD) in treatment of Parkinson’s disease (PD). CD is an inhibitor for enzyme decarboxylase, yet its mode of action is not entirely known although it is believed to involve enzyme shape recognition. The present work attempts to investigate the conformational preferences of CD. Tight geometry optimization at the density functional theory (DFT)/B3LYP/6-311[Formula: see text]G** level of theory has been carried out. The shallow nature of the potential energy surface (PES) and the presence of several local minima within a small energy range necessitate the launching of DFT-based molecular dynamics (MD) simulations. Two MD experiments were submitted for 35,000 points each. The complete trajectory in time domain of 10.5 ps is analyzed and discussed. The global minimum energy structure of CD is localized and identified by subsequent frequency calculations. The quantum theory of atom in molecules (QTAIMs) is used to extract and compare the quantum chemical topology features of the electron density distribution in CD and LD. Bonding characteristics are analyzed and discussed within the natural bond orbital (NBO) framework.

Sulfur dimers adsorbed on Au(111) as building blocks for sulfur octomers formation: A density functional study

2014 ◽  
Vol 141 (4) ◽  
pp. 044713 ◽  
Author(s):  
Carlos E. Hernandez-Tamargo ◽  
Ana Lilian Montero-Alejo ◽  
Daniel Codorniu Pujals ◽  
Hans Mikosch ◽  
Mayra P. Hernández
Keyword(s):  
Density Functional ◽  
Building Blocks ◽  
Functional Study ◽  
Density Functional Study

First-Principles Geometry Optimization of Polysilane

1988 ◽  
Vol 141 ◽  
Author(s):  
John W. Mintmire
Keyword(s):  
Total Energy ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Minimum Energy ◽  
Geometry Optimization ◽  
Functional Approach ◽  
Energy Structure ◽  
Atomic Orbitals ◽  
Local Density Functional

AbstractA first-principles approach is reviewed for calculating the total energy of chain polymers using a linear combination of atomic orbitals local-density functional approach. The geometry for the all-trans conformation of polysilane is optimized by finding the minimum energy structure using this method.

Density functional study of the structural properties of silver halides: LDA vs GGA calculations

2008 ◽  
Vol 10 (9) ◽  
pp. 1228-1235 ◽  
Author(s):  
L.A. Palomino-Rojas ◽  
M. López-Fuentes ◽  
Gregorio H. Cocoletzi ◽  
Gabriel Murrieta ◽  
Romeo de Coss ◽  
...  
Keyword(s):  
Structural Properties ◽  
Density Functional ◽  
Functional Study ◽  
Silver Halides ◽  
Density Functional Study

Density Functional Study on the Configurations of Nen (n=2~36) Clusters

2017 ◽  
Vol 727 ◽  
pp. 381-387
Author(s):  
Chang Ning Peng ◽  
Xing Rong Zheng
Keyword(s):  
Binding Energy ◽  
Density Functional ◽  
Energy Gap ◽  
Geometry Optimization ◽  
Basis Set ◽  
Functional Study ◽  
B3lyp Method ◽  
The Density Functional Theory ◽  
Quantum Chemistry Calculations ◽  
Average Bond

Based on the First-principles and the method of quantum chemistry calculations, using the B3LYP method and 6-31G basis set of the density functional theory (DFT), the configurations and binding energy of Nen (n=2~36) clusters are calculated and studied theoretically after the calculation of geometry optimization. By changing the atomic number n of the Nen (n=2~36) clusters, it obtained that the stable structures, the binding energy and HOMO - LUMO energy gap of the Nen (n=2~36) clusters under the same ideal conditions, and summarizes the change rule of the stable configurations, the binding energy and the average bond length of the Nen (n=2~36) clusters.

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