DFT and CCSD(T) electronic properties and structures of aluminum clusters: Alnx (n = 1–9, x = 0, ±1)

We have investigated the ability of PBE0, M05-class, and M06-class of density functional theory (DFT) to describe the geometries, vibrational frequencies, binding energies and electronic properties of aluminum clusters, Alnx (n = 2–9, x = 0, ±1). The DFT results are compared to those obtained from CCSD(T)/CBS calculations and experimental data when available. For Aln clusters (n ⩽ 7) the average error difference (UED) for the electron affinities and ionization potential compared to the experimental data are only 0.14 and 0.15 eV at PBE0/aug-cc-pVTZ level and 0.11 and 0.13, respectively for the CBST-Q calculations.