The performance of several common approximations for the exchange-correlation kernel within time-dependent density-functional theory is tested for elementary excitations in the homogeneous electron gas. Although the adiabatic local-density approximation gives a reasonably good account of the plasmon dispersion, systematic errors are pointed out and traced to the neglect of the wavevector depend...

The nuclear structure function F2A(x) has been studied in the Bjorken limit for (l, l) scattering on nuclei in the region of x > 1 and was found to be very sensitive to the information contained in the nucleon spectral function in nuclei, particularly the correlations between momenta and energies in the region of large momenta. Calculations were done in a local density approximation using two d...

This article starts with a brief history and idea interpretation of the Density Functional Theory (DFT), and then explains more detailedly about the original thought of Hohenberg and Kohn and their first and second theorem of the DFT. Next, it also introduces a methodology to treat the calculation based on DFT, which is the Kohn-Sham method based on the Local Density Approximation (LDA) treatme...

The adiabatic connection can be used in density functional theory to define the unknown ~exchange and! correlation density functional. Using conventional wave-function techniques, accurate estimates of thus defined ~exchange and! correlation energy densities can be obtained for specified systems. In this paper, numerical results are presented for the He and the Be atom, as well as the isoelectr...

We introduce a short-range correlation density functional defined with respect to a multi-determinantal reference which is meant to be used in a multi-determinantal extension of the Kohn–Sham scheme of density functional theory based on a long-range/short-range decomposition of the Coulomb electron–electron interaction. We construct the local density approximation for this functional and discus...

We consider the pairing Hamiltonian and systematically construct its density functional in the strong-coupling limit and in the limit of large particle number. In the former limit, the functional is an expansion into central moments of occupation numbers. In the latter limit, the functional is known from BCS theory. Both functionals are nonlocal in structure, and the nonlocalities are in the fo...

In this work, we have calculated ab initio the equation of state, the principal phonon modes, the effective charges and the temperature dependence of the specific heat for the III-Nitrides, by using the density-functional theory within the local density approximation, plane wave expansions and the pseudopotential method. A good agreement with the experiment and other calculations is obtained, w...

In this work, by using the density-functional theory within the local density approximation, plane wave expansions and the pseudopotential method, we present our preliminary results for the strain-induced shifts of the zone center phonon modes and of the effective charges on the III-Nitrides. Our results are in good agreement with the experiment as well as with other calculations, whenever a co...

Determining excited state properties of atomic clusters is a challenging problem. In general, the ground state structural properties of clusters are unknown and not subject to direct experimental probes. Without knowledge of these properties, it is not possible to predict accurate optical excitations in clusters. Here we present a real-space-pseudopotential method to determine the structural pr...