STRUCTURE AND VIBRATIONS OF FREE NIN CLUSTERS (N < 20)

Abstract

The binding energy, equilibrium geometry, and vibration frequencies of small free Nin clusters (n < 20) were calculated using interatomic interaction potentials calculated in an embedded atom method. Calculations of the energy parameter of stability АЕ2 and dissociation energy showed that the most energetically stable clusters are those with the magic numbers of atoms n = 4, 6, 13, 19. Calculations of atomic vibrations revealed that the dynamic contribution to the stability of clusters is determined by the minimum vibration frequency, whose extreme values fall on clusters with the magic numbers of atoms n = 4, 6, 13, 19. The maximum vibration frequency varies nonmonotonically and for clusters with n < 19 it has no clear extreme values. This result is consistent with available experimental data on stable structures of small and medium-sized metal clusters.