To the problem of tight binding potential parameters approbation: influence of the ratio between pair and many-body interaction on the process of the structure formation in binary Pd-Pt nanoparticles

Abstract

The reliability of the atomistic simulation is determined in terms of the correctness of the problem statement, including the choice of the interatomic interaction potential and its parameterization. In this paper, a detailed testing of the tight-binding potential parameters was carried out by means of studying the influence of the ratio between pair and many-body interactions on the process of the structure formation in binary Pd-Pt nanoparticles. Three parameterizations of the tight-binding potential for the cross parameters were selected: set (I) corresponded to the use of the Lorentz-Berthelot rule, sets (II) and (III) specified the scaling laws for the pair interaction parameters and the many-body interaction parameters, respectively. For sets (I) and (III), the surface segregation of palladium atoms was established, while the use of set (II) led to the formation of the Janus structure. In addition, differences in the formation of the local structure in binary Pd-Pt nanoparticles were established. Set (III) predicts the dominance of the local bcc structure. Radial distributions of the local density of Pd and Pt atoms in the Pd-Pt nanoparticles at a final temperature of 300 K were also calculated.

Keywords

• molecular dynamics method
• tight-binding potential
• pair interaction
• many-body interaction
• pd-pt nanoparticles
• structure formation