The von Weizsäcker Coefficient in Density Functional Theoryt
نویسندگان
چکیده
For any given potential, linear response theory tells us the size that the von Weizsäcker coefficient must assume in order to obtain the correct energy in the weak coupling limit. With this necessarily imposed choice, the quality of results is investigated as the coupling is strengthened. From the study of a number of model problems (the harmonic oscillator, the Yukawa well and the Mathieu potential) it is concluded that good results can be maintained to high couplings.
منابع مشابه
Kirzhnits gradient expansion for a D-dimensional Fermi gas
For an ideal D-dimensional Fermi gas under generic external confinement we derive the correcting coefficient (D − 2)/3D of the von Weizsacker term in the kinetic energy density. To obtain this coefficient we use the Kirzhnits semiclassical expansion of the number operator up to the second order in the Planck constant h̄. Within this simple and direct approach we determine the differential equati...
متن کاملAb initio study & Density functional investigational of Adenine & Thymine; Comparison of primitive Gaussian and NBO calculation
We have performed quantum-chemical ab initio in various basis sets at the Hartree-Fock andB3LYP levels for Adenine and Thymine with the program GAUSSIAN98. The Dipole,Quadrupole, Octapole and Hexadecapole moments and primitive in nine basis sets for thesemolecules are presented. The most stabilized forms of these molecules are observed in 6-311++G** basis set. We have evaluated coefficient hybr...
متن کاملNumerical analysis of the planewave discretization of orbital-free and Kohn-Sham models Part I: The Thomas-Fermi-von Weizsäcker model
We provide a priori error estimates for the spectral and pseudospectral Fourier (also called planewave) discretizations of the periodic Thomas-Fermivon Weizsäcker (TFW) model and of the Kohn-Sham model, within the local density approximation (LDA). These models allow to compute approximations of the ground state energy and density of molecular systems in the condensed phase. The TFW model is st...
متن کاملStructural and Optical Properties of polyvinyl alcohol doped silver ( PVA :Ag) film
The present paper investigates a detailed study on the optical properties of PVA/Ag nanocomposite films. In this interest , PVA/Ag nanocomposites with different ways of study ,the first prepared film by reduction 0.2M of Ag+ ions in 2 gm of PVA and study the transmission , absorption coefficient, refractive index, extinction coefficient, reflection, real & imaginary part of the dielectric const...
متن کاملStability of Atoms and Molecules in an Ultrarelativistic Thomas–fermi–weizsäcker Model
In the non relativistic case, some emphasis has been placed on the question of an appropriate choice of the coefficient λ of the gradient term connected to the kinetic energy. The non relativistic gradient correction λ(∇ρ)2/ρ was initially derived by Weizsäcker [14] with a value λ = 1, whereas the systematic gradient expansion by Kirznits [7, 6] leads to λ = 1/9. In the derivation of Tomishima ...
متن کامل