Interaction potentials from periodic density-functional theory calculations: Molecular-dynamics simulations of Au clusters deposited on the TiN (001) surface

Molecular-dynamics simulations of gold particles deposited on a TiN 001 surface have been accounted for through classical pair potentials describing the atom force field. The interaction between Ti–N, Ti–Ti, N–N, Au–Au, Au–Ti, and Au–N pairs was estimated by following a procedure in which the interaction energy between two sets of atoms is estimated from density-functional calculations performed with periodic boundary conditions using plane waves as basis set. The pair potentials were expressed as the sum of two contributions: long range in a Coulomb form and a short-range term, which included the rest of the energy contributions. Simulations of the TiN 001 isolated surface reproduced the already described surface relaxation, with a rippling parameter in agreement with that found from a purely first-principles approach. Simulations of gold deposition on such surfaces showed the formation of metal clusters with well-defined fcc structure and epitaxially grown.