Density functional studies of coinage metal nanoparticles: scalability of their properties to bulk

Density functional plane-wave calculations have been carried out for series of Cu _n ,Ag _n and Au _n particles containing up to 146 (Cu, Ag) and 225 (Au) atoms. Full geometry optimization has been performed for all particles starting from the structures created by cuts from the bulk. In line with previous studies, calculated average nearest-neighbour distances and cohesive energies of the particles linearly depend on such size-derived parameters as the average coordination number of metal atoms and the inverse of the mean particle radius, respectively. Rather accurate linear extrapolation of the observables under scrutiny to the bulk values has been achieved. However, we show that the scalability for particles made of various elements of the same d¹⁰s¹ electron configuration differs, e.g. for bond lengths in Au _n species it is noticeably less perfect than that for Cu _n and Ag _n ones. Implications of encountered structural peculiarities of the nanoparticles for their reactivity are outlined.