In this paper, the structural and electronic properties of P/SnBr2 heterojunctions were investigated using first-principles calculation method based on density functional theory (DFT). The band alignment heterojunction was type I. bandgap value 0.71 eV in DFT calculation. Furthermore, could be efficiently tuned by controlling an electric field biaxial strain. changed linearly with a certain ran...

In the present work, an extensive theoretical calculation study on Histidine-Histidine dipeptide in gas phase is done by using DFT method with Gaussian 98 program. Through investigations on the molecular geometries of this molecule it is found that there is six rings in the molecules not two rings. The presence of four intramolecular hydrogen bonds is responsible for the formation of additional...

Using the Density Functional Theory (DFT) level by means of 3-21G, 6-31G and 6-31+G (d) basissets, the structural optimization of isolated Pyrazole and Pyrazoline was done in the gas phase. Then,the calculation about the solvent effect on the stability energies of Pyrazole and Pyrazoline wasperformed for the ten solvents using PCM model method at B3LYP/6-31+G(d) and then the dielectriceffects o...

We propose and consolidate a definition of the discrete fractional Fourier transform that generalizes the discrete Fourier transform (DFT) in the same sense that the continuous fractional Fourier transform generalizes the continuous ordinary Fourier transform. This definition is based on a particular set of eigenvectors of the DFT matrix, which constitutes the discrete counterpart of the set of...

Kohn-Sham density functional theory (KS-DFT)[1, 2] is an efficient and usefully accurate electronic structure method, because it replaces the interacting Schrödinger equation with a set of single-particle orbital equations. Calculations with several hundred atoms are now routine, but there is always interest in much larger systems. Many such systems are treated by a lower-level method, such as ...

We have investigated the electronic structure and thermodynamic properties of supercell of the -Al2O3 by first-principles calculation in framework of density functional theory (DFT) and full potential linearized augmented plane wave (FP-LAPW) with generalized gradient approximation (GGA) and by quasi-harmonic Debye model. Our calculated value for direct band gap of α-Al2O3 is 7.2 eV which i...

In this work, we present firstly a study based on the calculation of the local spin densities of radical cations, which is known as a good measure of reactivity for coupling reactions, to obtain a theoretical basis for the one-step formation of poly(3.6-carbazole) and derivatives. Then we detail a DFT theoretical study of the geometric and electronic properties of oligomers based on carbazole a...

This paper highlights the experimental and theoretical studies on the Melamine treated Active Carbon (MAC) support for an Au-Cu bimetallic catalyst in acetylene hydrochlorination reaction. Compared to the original Active Carbon (AC) loaded with the same amount of 0.1wt% Au and 1.0wt% Cu,  MAC supported catalyst(MACH), wherein Carbon/C6...

The scaling of dynamical correlation energy in molecules obtained by the correlation functionals of density functional theory (DFT) is examined. The approach taken is very similar to the scaled external correlation method of Brown and Truhlar but is based on the observation that DFT correlation functionals, especially the LYP, appear to represent the dynamical portion of the correlation energy ...

The mechanism of the iron-catalyzed cross-coupling of alkyl halides with aryl Grignard reagents is studied by a combination of GC monitoring and DFT calculation. Herein, we investigate two possible reaction pathways, the regular oxidative addition (OA) pathway and the atom transfer (AT) pathway that might occur in the rate-limiting step. The computational studies revealed that the AT pathway re...