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THE LIMITS OF THE EXTENDED HÜCKEL THEORY TO CALCULATE THE TOTAL DENSITY OF STATES OF MEDIUM-SIZED MOLECULES
(Sociedad Chilena de Química, 2006)
Modified local exchange and kinetic energy functionals for atomic systems
(Elsevier, 1997)
New local functionals for the kinetic and Hartree-Fock exchange energy of atoms are proposed. They are of the following general form: T[ρ] =22/3CF ∫ ∑σρ5/3 σf(r,ρ σ)dr. The function f(r,ρσ), except for two adjustable ...
Theoretical methods for calculations of optical phonons in BiOBr: Analysis and correction of propagated errors
(2018-08-01)
Theoretical and experimental methods were employed to investigate the vibrational modes of BiOBr. Wavenumber prediction and assignments of the infrared and Raman modes were performed using density functional theory and ...
Calculation of the statistical properties in intermittency using the natural invariant density
(Multidisciplinary Digital Publishing Institute, 2021-06)
We use the natural invariant density of the map and the Perron–Frobenius operator to analytically evaluate the statistical properties for chaotic intermittency. This study can be understood as an improvement of the previous ...
Edge effects in bilayer graphene nanoribbons: Ab initio total-energy density functional theory calculations
(AMER PHYSICAL SOC, 2009)
We show that the ground state of zigzag bilayer graphene nanoribbons is nonmagnetic. It also possesses a finite gap, which has a nonmonotonic dependence with the width as a consequence of the competition between bulk and ...
Reactivity indices and response functions in density functional theory
(Elsevier, 1998)
The hardness and softness quantities defined in density functional theory are discussed. A new scheme to calculate the hardness and softness hierarchies without resorting to the finite difference approximation is outlined. ...
The limits of the extended hückel theory to calculate the total density of states of medium-sized molecules
(Sociedad Chilena de Química, 2006)
Two medium-sized molecular systems X60 (X=C,N) were analyzed using Extended Hückel, Density Functional and ab initio Hartree-Fock methods. The aim of the work was to test the reliability of the EHT methodology to calculate ...