scholarly journals Exact exchange potential evaluated from occupied Kohn-Sham and Hartree-Fock solutions

2011 ◽  
Vol 83 (6) ◽  
Author(s):  
M. Cinal ◽  
A. Holas

The phonon spectrum of sodium is calculated in the harmonic approximation. The effective interaction between the ions is separated into direct two-body forces between bare ions and effective attraction due to the presence of conduction electrons. Careful treatment of the two-phonon processes includes the calculation of the electron-phonon scattering based on the pseudo-potential method and the screening effects due to the interaction between electrons by the Hartree-Fock approximation with a screened exchange potential. Comparison of the results for sodium with neutron diffraction measurements and a previous calculation by Toya shows good agreement on the whole. It is hoped that this method may be applied to some other metals.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
K. M. Hanna ◽  
S. H. M. Sewailem ◽  
R. Hussien ◽  
L. I. Abou-Salem ◽  
Asmaa G. Shalaby

The interaction of nucleon-nucleon (NN) has certain physical characteristics, indicated by nucleon, and meson degrees of freedom. The main purpose of this work is calculating the ground-state energies of  12H and  24He through the two-body system with the exchange of mesons (π, σ, and ω) that mediated between two nucleons. This paper investigates the NN interaction based on the quasirelativistic decoupled Dirac equation and self-consistent Hartree-Fock formulation. We construct a one-boson exchange potential (OBEP) model, where each nucleon is treated as a Dirac particle and acts as a source of pseudoscalar, scalar, and vector fields. The potential in the present work is analytically derived with two static functions of meson, the single-particle energy-dependent (SPED) and generalized Yukawa (GY) functions; the parameters used in meson functions are just published ones (mass, coupling constant, and cutoff parameters). The theoretical results are compared to other theoretical models and their corresponding experimental data; one can see that the SPED function gives more satisfied agreement than the GY function in the case of the considered nuclei.


2015 ◽  
Vol 142 (2) ◽  
pp. 024318 ◽  
Author(s):  
Daeheum Cho ◽  
Kyoung Chul Ko ◽  
Yasuhiro Ikabata ◽  
Kazufumi Wakayama ◽  
Takeshi Yoshikawa ◽  
...  

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