Hybrid Density Functionals for Clusters of Late Transition Metals: Assessing Energetic and Structural Properties

We present the first application of hybrid density functional theory (DFT) methods to larger transition-metal clusters. To assess such functionals for this class of systems, we compare the performance of three modern hybrid DFT methods (PBE0, TPSSh, M06) and their semilocal counterparts (PBE, TPSS, M06L) regarding average bond distances and binding energies per atom for a series of octahedral model clusters Mn (M = Ni, Pd, Pt; n = 13, 38, 55, 79, 116). With application to large particles in mind, we extrapolated the results to their respective bulk limits and compared them to experimental values. In some cases, average nearest-neighbor distances are notably overestimated by the PBE0 and M06 hybrid functionals. Results on energies allow a grouping of the tested functionals into sets of similar behavior for the three metals studied. Among the methods examined, the TPSSh hybrid density functional shows the best overall performance.