A computational study of the Au+Xe ionic system has been performed using newly developed coupled-cluster methods and relativistic model core potentials, with extra basis functions optimized to afford superior polarizabilities. Potential energy curves for the dissociation of Au+Xe were studied at different levels of theory, and molecular properties (bond length and harmonic vibrational frequency) were calculated. Wave functions were analyzed using the natural bond orbital method. The nature of bonding in this system is discussed.