Inhomogeneity Correction to Exchange Potential

1970 ◽  
Vol 2 (2) ◽  
pp. 545-546 ◽  
Author(s):  
J. W. Darewych
Keyword(s):  
Exchange Potential ◽  
Inhomogeneity Correction

scholarly journals Electronic and optical properties of vacancy ordered double perovskites A2BX6 (A = Rb, Cs; B = Sn, Pd, Pt; and X = Cl, Br, I): a first principles study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Faizan ◽  
K. C. Bhamu ◽  
Ghulam Murtaza ◽  
Xin He ◽  
Neeraj Kulhari ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
First Principles ◽  
Density Functional ◽  
Perovskite Solar Cells ◽  
Dielectric Constants ◽  
Maximum Efficiency ◽  
Exchange Potential ◽  
Double Perovskites ◽  
Electronic And Optical Properties

AbstractThe highly successful PBE functional and the modified Becke–Johnson exchange potential were used to calculate the structural, electronic, and optical properties of the vacancy-ordered double perovskites A2BX6 (A = Rb, Cs; B = Sn, Pd, Pt; X = Cl, Br, and I) using the density functional theory, a first principles approach. The convex hull approach was used to check the thermodynamic stability of the compounds. The calculated parameters (lattice constants, band gap, and bond lengths) are in tune with the available experimental and theoretical results. The compounds, Rb2PdBr6 and Cs2PtI6, exhibit band gaps within the optimal range of 0.9–1.6 eV, required for the single-junction photovoltaic applications. The photovoltaic efficiency of the studied materials was assessed using the spectroscopic-limited-maximum-efficiency (SLME) metric as well as the optical properties. The ideal band gap, high dielectric constants, and optimum light absorption of these perovskites make them suitable for high performance single and multi-junction perovskite solar cells.

Renormalization method for inhomogeneity correction of MR images

2001 ◽  
Author(s):  
Dongqing Chen ◽  
Lihong Li ◽  
Daeki Yoon ◽  
J. H. Lee ◽  
Zhengrong Liang
Keyword(s):  
Mr Images ◽  
Inhomogeneity Correction ◽  
Renormalization Method

Liver MRI segmentation with edge-preserved intensity inhomogeneity correction

2017 ◽  
Vol 12 (4) ◽  
pp. 791-798 ◽  
Author(s):  
Hui Liu ◽  
Pinpin Tang ◽  
Dongmei Guo ◽  
HaiXia Liu ◽  
Yuanjie Zheng ◽  
...  
Keyword(s):  
Intensity Inhomogeneity ◽  
Liver Mri ◽  
Mri Segmentation ◽  
Inhomogeneity Correction

Local Density Approximations for the Energy of a Periodic Coulomb Model

2003 ◽  
Vol 13 (08) ◽  
pp. 1185-1217 ◽  
Author(s):  
Olivier Bokanowski ◽  
Benoît Grebert ◽  
Norbert J. Mauser
Keyword(s):  
Kinetic Energy ◽  
Local Density ◽  
Exchange Energy ◽  
Asymptotic Approximations ◽  
Exchange Potential ◽  
Energy Term ◽  
Local Exchange ◽  
Coulomb Model ◽  
Local Density Approximations ◽  
Number Of Particles

We deal with local density approximations for the kinetic and exchange energy term, ℰ kin (ρ) and ℰ ex (ρ), of a periodic Coulomb model. We study asymptotic approximations of the energy when the number of particles goes to infinity and for densities close to the constant averaged density. For the kinetic energy, we recover the usual combination of the von-Weizsäcker term and the Thomas–Fermi term. Furthermore, we justify the inclusion of the Dirac term for the exchange energy and the Slater term for the local exchange potential.

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