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...

A. S. Foster,1,2 T. Trevethan,3,4 and A. L. Shluger3,4 1Laboratory of Physics, Helsinki University of Technology, P.O. Box 1100, 02015 Helsinki, Finland 2Department of Physics, Tampere University of Technology, P.O. Box 692, 33101 Tampere, Finland 3Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom 4WPI-AIMR Tohoku University, 2-1-1 Kat...

While the Local Density Approximation LDA+U method is well established for Mott insualtors with well localized orbitals, its application to weakly correlated metals is questionable. By extending the Stoner approach to LDA+U, we show that LDA+U enhances the Stoner factor, while reducing the density of states. The most important correlation effects in metals, fluctuation induced mass renormalizat...

Dynamical correlations in the homogeneous electron gas are a central issue in time-dependent density functional theory and are investigated here by evaluating exactly the leading corrections to the RPA proper polarizability. We obtain Im e(k ,v) at arbitrary k and v outside the ~single! particle-hole excitation spectrum. We calculate the imaginary part of the local field factor Im G(k ,v) and c...

In this research, the complexation of a new recently synthesized phenothiazine with 10 different metals was evaluated by Density functional theory. At the first step, the structures of 6,15-diazabenzo[a][1,4]benzothiazino[3,2-c]phenothiazine, cations and their complexes with the mentioned material were optimized geometrically. Then, IR calculations were performed on them to obtain the values of...