We introduce a novel methodology to formally specify complex multiagent systems. Our approach allows us to redefine computational problems in terms of agents that perform certain tasks. In our view, a system is formed by the combination of atomic and complex agents. Atomic agents are in charge of executing atomic tasks while complex agents reunite and summarize the properties of their underlyin...

A new simple algorithm to extrapolate the electronic charge density in ab initio molecular dynamics runs is proposed. The self-consistent charge density is decomposed in two parts, the first part is the sum of the atomic charge densities, and the second is its difference with the latter. The charge at time t + dt is constructed using the sum of the atomic charges and a second order extrapolatio...

The role of orbital polarization for ultrafast charge transfer between an atomic adsorbate and a substrate is explored. Core hole clock spectroscopy with linearly polarized x-ray radiation allows to selectively excite adsorbate resonance states with defined spatial orientation relative to the substrate surface. For c(4 x 2)S/Ru(0001) the charge transfer times between the sulfur 2s(-1)3p*+1 anti...

The stability of surface structure and space-charge distribution in free TiO2 nanoparticles are investigated for both rutile and anatase phases using a variable-charge interaction potential in which atomic charges vary dynamically depending on their environment. We find the dynamic charge transfer: ~i! enhances atomic diffusion at surfaces of the spherical nanoparticles at high temperatures; an...

The molecular geometry of complex of adenine with 8 water molecules was calculated with Hartree-Fock (HF). The standard 6-31G(d) basis set has been employed. The existence of C-H…O Hydrogen bonds between the water molecules and the hydrophobic part of nucleobase is stablished. We optimized structures and computed interaction energies of all complexes of adenine with water molecules step by step...