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.