Relativistic electronic structure of an icosahedral Au₁₂Pd cluster

Multicenter symmetry-adapted angular momentum basis functions have been generated for the icosahedral double point group. These basis functions are used to obtain the Dirac molecular orbitals for the icosahedral Au₁₂Pd and Au₁₃ clusters via the self-consistent-field Dirac scattered wave method. The Au₁₂Pd cluster should be diamagnetic due to a singlet ground state, while the Au₁₃ cluster is paramagnetic. The calculated cluster electronegativities (χ) for Au₁₂Pd and Au₁₃ are almost identical, being 7.62 and 7.68 eV, respectively. However, the calculated softness (S) is equal to 4.0 eV^-1 for Au₁₂Pd, and equal to 3.4 eV^-1 for Au₁₃. These results indicate that Au₁₂Pd should be more reactive than Au₁₃.