Keynote: Adding electronic effects in classical Molecular Dynamics simulations

EDUARDO M BRINGA

Santiago

Simposio; Segundo Simposio de Nanotecnología; 2019

Universidad Mayor, Chile

Atomistic Classical MolecularDynamics (MD) simulations allow the study of systems relevant tonanotechnology, with the possibility of including millions of atoms andcomplex, realistic, defects. Usually, the interactions amongst atoms do notinclude explicit electronic effects, which are including in a simplified,effective way, in the empirical potentials. However, thanks to advances in bothhardware and software, there is an increasing effort to include relevantelectronic effects. In this presentation a few caseswill be discussed, as examples of the inclusion of electronic effects in MD:(i) reactive, bond-order potentials including charge transfer, (ii) modeling ofelectrons as a fluid within a two-temperature model (TTM), and (iii) magneticsystems. Regarding reactive systems, bondstrength depends on the type and number of neighbors, and charge transfer canmodify mechanical properties significantly. As an alternative, electrons can beconsidered as a fluid in a ?Two-Temperature Model?, coupled to MD (TTM-MD), inorder to simulate irradiation of materials with swift heavy ions. However,there are still many unknowns for the modeling of non-equilibrium electrons innanostructures.  Finally, a simplifiedmodel of magnetism can be achieved adding a classical spin to every atom in thesystem. This allows the study of magnetization in finite systems, and also theinclusion of complex defects like dislocations.Limitations and futureperspectives will be discussed for each case.