Ab initio correlated study of the Al13H− anion: Isomers, their kinetic stability and vertical detachment energies

We report correlated ab initio calculations for the Al13H− cluster anion isomers, their kinetic stability and vertical detachment energies (VDEs). Of the two most energetically favored anion structures involving H atom in terminal and threefold bridged sites of the icosahedral Al13−, the higher energy ‘threefold bridged’ isomer is shown to be of low kinetic stability. Our results are consistent with the recent photoelectron spectroscopy (PE) study of Grubisic et al. who observed two distinct Al13H− isomers, one of them identified as ‘metastable’. The VDE energies computed at the CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pVDZ level for the ‘terminal’ and ‘threefold bridged’ Al13H− isomers of 3.21 and 2.32 eV are in good agreement with those determined in the PE study.