Transition-metal complexes containing (C-C)&rarrM -interactions have potential applications in both catalysis and the activation and cleavage of C-C bonds. Fully characterising the bonding and interactions in complexes containing such (C-C)&rarrM -interactions is vital to understand their chemical behaviour. As a result a high-resolution experimental X-ray charge density study has been undertaken on [Rh(Binor-S)(PCy3)][HCB 11Me11] (Binor-S = 1,2,4,5,6,8-dimetheno-s-indacene) which contains a (C-C)&rarrRh interaction. The data are analysed using Bader's "Atoms in Molecules" (AIM) approach with particular attention paid to the interactions around the rhodium centre. The results provide clear evidence for the (C-C)&rarrRh interaction in the solid-state which is classified as a weak covalent interaction. These results are supported by theoretical calculations.