Validation study of the ability of density functionals to predictthe planar-to-three-dimensional structural transitionin anionic gold clusters

摘要

As gold clusters increase in size, the preferred structure changes from planar to three-dimensionaland, for anionic clusters, Aun-, the two-dimensional(2D) —> three-dimensional (3D) transition isfound experimentally to occur between n=11 and n=12. Most density functionals predict thatplanar structures are preferred up to higher n than is observed experimentally, an exception being thelocal spin density approximation. Here we test four relatively new functionals for this feature, inparticular, M05, M06-L, M06, and SOGGA. We find that M06-L, M06, and SOGGA all predict the2D-> 3D transition at the correct value of n. Since the M06-L and M06 functionals have previouslybeen shown to be reasonably accurate for transition metal bond energies, main group atomizationenergies, barrier heights, and noncovalent interaction energies, and, since they are here shown toperform well for the s-d excitation energy and ionization potential of Au atoms and for the size ofAun- clusters at which the 2D —> 3D transition occurs, they are recommended for simulatingprocesses catalyzed by gold clusters.