Using calculations from first principles, we herein consider the bond made between thiolat e with a range of different Au clusters, with a particular focus on the spin moments inv olved in each case. For odd number of gold atoms, the clusters show a spin moment of 1.~ $mu_B$. The variation of spin moment with particle size is particularly dramatic, with t he spin moment being zero for even numbers of gold atoms. This variation may be linked w ith changes in the odd-even oscillations that occur with the number of gold atoms, and is associated with the formation of a S-Au bond. This bond leads to the presence of an extra electron that is mainly sp in character in the gold part. Our results sugg est that any thiolate-induced magnetism that occurs in gold nanoparticles may be locali zed in a shell below the surface, and can be controlled by modifying the coverage of the thiolates.
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