Relativistic coupled cluster studies are performed for the structures, dissociation energies, ionization potentials and electron affinities for Au, Au2 and Au3. The calculations show that the upward shifts of the ionization potentials and electron affinities of Aun clusters by approximately 2 eV compared to Cun or Agn base on relativistic effects. Au3+ is predicted to adopt a trigonal planar structure (D3h, A11), Au3 a E⊗ε Jahn–Teller distorted structure (C2v,2A1) 0.1 eV below the linear Σu+2 arrangement, and Au3− adopts a linear structure (1Σg+).