Determination of the energy landscape of Pd12Pt1 using a combined genetic algorithm and threshold energy method

Artikel i vetenskaplig tidskrift, 2013

In this work we present a thorough exploration of the potential energy surface (PES) of Pd-Pt bimetallic nanoparticles at the specific composition Pd12Pt1, using the combination of a genetic algorithm and the threshold method for global optimization and exploration of the barrier structure, employing the semi-empirical Gupta many-body potential for modeling the interatomic interactions. The structural and energetic analysis of Pd12Pt1 nanoparticles, including binding energies (E-b), symmetries and common-neighbor analysis (CNA) allowed us to identify a large set of representative structures of local minima, with an icosahedral motif found to be the putative global minimum for Pd12Pt1. A detailed study of the icosahedral motif was carried out by an exhaustive exploration of low energy isomers, in order to understand qualitatively structural interconversion. 2-D tree (disconnectivity) graphs are plotted to map the structures of minima on the PES of Pd12Pt1. DFT calculations were performed on representative structures to establish the energetic hierarchy and structural stability.