%0 Journal Article %A Knoppe, Stefan %A Malola, * Sami %A Lehtovaara, Lauri %A Bürgi, Thomas %A Häkkinen, Hannu %T Electronic Structure and Optical Properties of the Thiolate-Protected Au28(SMe)20 Cluster %J Journal of Physical Chemistry A %@ 1089-5639 %V 117 %N 40 %P 10526-10533 %D 2013 %U http://pubs.acs.org/doi/abs/10.1021/jp407494v %R 10.1021/jp407494v %U http://archive-ouverte.unige.ch/unige:30762 %X The recently reported crystal structure of the Au28(TBBT)20 cluster (TBBT: para-tert-butylbenzenethiolate) is analyzed with (Time-Dependent-) Density Functional Theory (TD-DFT). Bader charge analysis reveals a novel trimeric Au3(SR)4 binding motif. The cluster can be formulated as Au14(Au2(SR)3)4(Au3(SR)4)2. The electronic structure of the Au146+ core and the ligand-protected cluster were analyzed and their stability can be explained by formation of distorted eight-electron superatoms. Optical absorption and Circular Dichroism (CD) spectra were calculated and compared to the experiment. Assignment of handedness of the intrinsically chiral cluster is possible.