Asymmetry in Time Evolution of Magnetization in Magnetic Nanostructures.

Strong interest in nanomagnetism stems from the promise of high storage densities of information through control of ever smaller and smaller ensembles of spins. There is a broad consensus that the Landau-Lifshitz-Gilbert equation reliably describes the magnetization dynamics on classical phenomenological level. On the other hand, it is not so evident that the magnetization dynamics governed by this equation contains built-in asymmetry in the case of broad topology sets of symmetric total energy functional surfaces.

Structure, vibrations and Raman modes in electron doped metal phthalocyanines.

Identifying and understanding the vibrational frequency shifts caused by electron addition to metal phthalocyanine (MPc) molecules is the main goal of the present work. Among other things, it should be useful in establishing the amount of charge-transfer level recently reported in potassium doped solid MPc films. Choosing MgPc as our working case, we calculated by density functional methods the full vibration spectrum of the neutral and of the negatively charged molecule, with and without Jahn-Teller distortion.

Strong correlations in electron doped phthalocyanine conductors near half filling.

We propose that electron doped nontransition metal phthalocyanines such as ZnPc and MgPc, similar to those very recently reported, should constitute novel strongly correlated metals. Because of orbital degeneracy, Jahn-Teller coupling, and Hund's rule exchange, and with a large on-site Coulomb repulsion, these molecular conductors should display, particularly near half filling at two electrons/molecule, very unconventional properties, including Mott insulators, strongly correlated superconductivity, and other intriguing phases.

Electric fields with ultrasoft pseudo-potentials: applications to benzene and anthracene.

We present density-functional perturbation theory for electric field perturbations and ultra-soft pseudopotentials. Applications to benzene and anthracene molecules and surfaces are reported as examples. We point out several issues concerning the evaluation of the polarizability of molecules and slabs with periodic boundary conditions.