Interband and polaronic excitations inYTiO3from first principles

Electron-hole excitations and optical spectra from first principles

We present a recently developed approach to calculate electron-hole excitations and the optical spectra of condensed matter from first principles. The key concept is to describe the excitations of the electronic system by the corresponding oneand two-particle Green’s function. The method combines three computational techniques. First, the electronic ground state is treated within density-functi...

First-principles modeling of magnetic excitations in Mn12

Dynamical magnetic excitations of nanostructures from first principles.

Within time-dependent density functional theory, combined with the Korringa-Kohn-Rostoker Green functions, we devise a real space method to investigate spin dynamics. Our scheme enables one to deduce the Coulomb potential which assures a proper Goldstone mode is present. We illustrate with application to 3d adatoms and dimers on Cu(100).

Neutral and charged excitations in carbon fullerenes from first-principles many-body theories.

We investigate the accuracy of first-principles many-body theories at the nanoscale by comparing the low-energy excitations of the carbon fullerenes C(20), C(24), C(50), C(60), C(70), and C(80) with experiment. Properties are calculated via the GW-Bethe-Salpeter equation and diffusion quantum Monte Carlo methods. We critically compare these theories and assess their accuracy against available p...

First principles simulations

In this paper we outline the major features of the "ab-initio" simulation scheme of Car and Parrinello, focusing on the physical ideas and computational details at the basis of its efficiency and success. We briefly review the main applications of the method. We discuss the limitations of the standard scheme, as welt as recent developments proposed in order to extend the reach of the method. Mo...