Molecular quadrupole moments, second moments, and diamagnetic susceptibilities evaluated using the generalized gradient approximation in the framework of Gaussian density functional method

1996 ◽  
Vol 105 (8) ◽  
pp. 3206-3210 ◽  
Author(s):  
Giorgio de Luca ◽  
Nino Russo ◽  
Emilia Sicilia ◽  
Marirosa Toscano
Keyword(s):  
Density Functional ◽  
Density Functional Method ◽  
Functional Method ◽  
Quadrupole Moments ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
Second Moments ◽  
Gaussian Density

scholarly journals Electronic and optical properties of Mn–S co-doped anatase TiO2 from first-principles calculations

2016 ◽  
Vol 34 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Guohao Wu ◽  
S.K. Zheng ◽  
Xiaobing Yan
Keyword(s):  
Optical Properties ◽  
Visible Light ◽  
Density Functional ◽  
Density Functional Method ◽  
Functional Method ◽  
Potential Candidate ◽  
Generalized Gradient ◽  
Electronic And Optical Properties ◽  
Enhanced Absorption ◽  
Co Doped

AbstractThe electronic and optical properties of Mn–S co-doped anatase TiO2 were calculated using the plane-wave-based ultrasoft pseudopotential density functional method within its generalized gradient approximation (GGA). The calculated results show that the band gap of Mn–S co-doped TiO2 is larger than that of the pure TiO2, and two impurity bands appear in the forbidden band, one of which above the valence band plays a vital role for the improvement of the visible light catalytic activity. The Mn–S co-doped anatase TiO2 could be a potential candidate for a photo catalyst because of its enhanced absorption ability of visible light.

Optical Properties of Heterodiamond BC3 from First-Principles

2013 ◽  
Vol 749 ◽  
pp. 551-555 ◽  
Author(s):  
Lei Li ◽  
Wen Xue Li ◽  
Dong Han ◽  
She Wei Xin ◽  
Yi Yang ◽  
...  
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Density Functional Method ◽  
Functional Method ◽  
First Principles Calculation ◽  
Optical Absorption Coefficient ◽  
Generalized Gradient ◽  
Exchange Correlation ◽  
Electron Deficiency

First principles calculation for optical properties of a tetragonal BC3 (t-BC3) are performed through the pseudopotential density functional method. The exchange correlation potential is treated by the Perdew-Burke-Eruzerhof form of generalized gradient approximation. The basic optical constants including the real and imaginary parts of the dielectric function, the optical absorption coefficient, the reflectivity and the energy loss function were calculate in detail by this method. The results indicate that the t-BC3 is an optical anisotropic crystal and its electron-deficiency characteristic can cause some features in low energy region.

Anion-Cation Replacement Effect on the Structural and Optoelectronic Properties of the LiMX2 (M = Al, Ga, In; X = S, Se, Te) Compounds: A First Principles Study

2018 ◽  
Vol 73 (7) ◽  
pp. 645-655 ◽  
Author(s):  
Amjad Khan ◽  
M. Sajjad ◽  
G. Murtaza ◽  
A. Laref
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Density Functional Method ◽  
Covalent Bond ◽  
Functional Method ◽  
Generalized Gradient ◽  
Lattice Constants ◽  
Crystal Unit Cell ◽  
Ionic Bonds ◽  
Structural And Optoelectronic Properties

AbstractIn the chalcopyrite (or tetragonal) phase, different physical properties of the ternary LiMX2 (M = Al, Ga, In and X = S, Se, Te) compounds are studied by the very accurate density functional method. The optimized lattice constants and the bandgaps are close to the existing experimental data. In addition, for most of the LiMX2 compounds, when the cations change from Al to In and anions from S to Te, the lattice constant and equilibrium volume for the crystal unit cell increase whereas the bulk modulus decreases. Using different generalized gradient approximations, the band structure calculations are performed. Generally, it was observed that there exists a decreasing tendency of the bandgap energies except for the LiAlSe2, LiInSe2, and LiGaTe2 compounds due to the change from Al to In as well as the change from S to Te. The bonding analysis shows that ionic bonds are present between the Li-X atoms, while a covalent bond exists between the M cations and X anions. The optical properties of the compounds are studied by calculating the real and imaginary components of the refractive index, reflectivity, optical conductivity, and birefringence. In addition, the optical properties from the calculations show that these materials are appropriate applicants to be utilized as Bragg’s reflector or applied in optoelectronic and solar cell technology.

Sign in / Sign up

Export Citation Format

Share Document