scholarly journals London dispersion forces without density distortion: a path to first principles inclusion in density functional theory

2020 ◽  
Vol 224 ◽  
pp. 145-165
Author(s):  
Derk Pieter Kooi ◽  
Paola Gori-Giorgi
Keyword(s):  
Ground State ◽  
First Principles ◽  
Density Functional ◽  
Dispersion Forces ◽  
Density Functionals ◽  
Functional Theory ◽  
Exchange Correlation ◽  
State Densities ◽  
London Dispersion ◽  
London Dispersion Forces

We analyse a path to construct density functionals for the dispersion interaction energy from an expression in terms of the ground state densities and exchange–correlation holes of the isolated fragments.

scholarly journals Hydrogen storage on platinum decorated graphene: A first-principles study

BIBECHANA ◽  
2014 ◽  
Vol 11 ◽  
pp. 113-122 ◽  
Author(s):  
S Lamichhane ◽  
N Pantha ◽  
NP Adhikari
Keyword(s):  
Binding Energy ◽  
First Principles ◽  
Density Functional ◽  
Pristine Graphene ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Exchange Correlation ◽  
London Dispersion ◽  
Quantum Espresso ◽  
London Dispersion Forces

Adsorption of gaseous/molecular hydrogen on platinum (Pt) decorated and pristine graphene have been studied systematically by using density functional theory (DFT) level of calculations implemented by Quantum ESPRESSO codes. The Perdew-Burke-Ernzerhof (PBE) type generalized gradient approximation (GGA) exchange-correlation functional and London dispersion forces have been incorporated in the DFT-D2 level of algorithm for short and long range electron-electron interactions, respectively. With reference to the binding energy of Pt on different symmetry sites of graphene supercells, the bridge (B) site has been predicted as the best adsorption site. In case of 3×3 supercell of graphene (used for detail calculations), the binding energy has been estimated as 2.02 eV. The band structure and density of states calculations of Pt adatom graphene predict changes in electronic/magnetic properties caused by the atom (Pt). The adatom (Pt) also enhances the binding energy per hydrogen molecule in Pt-graphene comparing to that in pristine graphene and records the values within the range of 1.84 eV to 0.13 eV for one to eight molecules, respectively. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10389 BIBECHANA 11(1) (2014) 113-122

Current-density dependent exchange-correlation functionals

1996 ◽  
Vol 74 (6) ◽  
pp. 995-997 ◽  
Author(s):  
Axel D. Becke
Keyword(s):  
Density Functional Theory ◽  
Current Density ◽  
First Principles ◽  
Density Functional ◽  
Chem Phys ◽  
Density Functionals ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Key Words Density ◽  
Natural Way

Previous models for exchange (Becke and Roussel, Phys. Rev. A: 39, 3761 (1989)) and for correlation (Becke, J. Chem. Phys. 88, 1053 (1988)) are, in a simple and natural way, generalized to include explicit dependence on current density J. First-principles incorporation of J into exchange-correlation density functionals, as proposed here, is crucial for further progress in the study of magnetic effects in density-functional theory. Key words: density-functional theory, exchange-correlation functionals, current density.

Electronic structure of cubic BaTbO3 from first-principles pseudopotential calculations

2006 ◽  
Vol 84 (2) ◽  
pp. 115-120 ◽  
Author(s):  
G Y Gao ◽  
K L Yao ◽  
Z L Liu
Keyword(s):  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Pseudopotential Calculations ◽  
Correlation Potential ◽  
Density Contour

First-principles calculations of the electronic structure are performed for cubic BaTbO3 using the plane-wave pseudopotential method within the framework of density functional theory and using the generalized gradient approximation for the exchange-correlation potential. Our calculations show that cubic BaTbO3 is metallic, and that this metallic character is mainly governed by the Tb 4f electrons and the hybridization between the Tb 5d and O 2p states. From the analysis of the density of states, band structure, and charge density contour, we find that the chemical bonding between Tb and O is covalent while that between Ba and TbO3 is ionic. PACS Nos.: 71.15.Mb, 71.20.-b

scholarly journals First-principles Study of Electronic and Magnetic Properties of Manganese Decorated Graphene

2016 ◽  
Vol 3 (1) ◽  
pp. 24 ◽  
Author(s):  
Bishnu Prasad Paudel ◽  
Nurapati Pantha ◽  
Narayan Prasad Adhikari
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Density Functional ◽  
Geometrical Structures ◽  
Functional Theory ◽  
Electronic And Magnetic Properties ◽  
Weak Binding ◽  
London Dispersion ◽  
The Stability ◽  
Quantum Espresso

<p>The functionalization of graphene by the addition of Manganese (Mn) atom to its surface has been investigated computationally by using density-functional theory (DFT) based first-principles method within DFT-D2 level of approximations. The calculations have been computed employing the Quantum ESPRESSO codes. The stability, geometrical structures, electronic and magnetic properties of pure and Mn adatom graphene systems have been studied. From the information of adsorption energies of Mn atom on the different sites of graphene, the top site is found to be the most favorable one for its adsorption. Present study finds that the London dispersion interaction plays a major role in the weak binding of Mn on graphene. The study of electronic and magnetic properties of Mn decorated graphene shows that the conduction and valence band are overlapped with finite density of states (DOS) at Fermi level. The dissimilar DOS for up and down spin calculations quantify magnetic moment as 5.48 μ<sub>B</sub> which is consistent with the previous study</p><p>Journal of Nepal Physical Society Vol.3(1) 2015: 24-34</p>

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