Abstract We have identified interatomic Coulombic decay (ICD) processes in the ArKr dimer following Ar 2p Auger decay, using momentum-resolved electron-ion-ion coincidence spectroscopy and simultaneously determining the kinetic energy of the ICD electron and the KER between Ar 2+ and Kr + . We find that the spin-conserved ICD processes in which Ar 2+ (3p −3 3d) 1 P and 3 P decay to Ar 2+ (3p −2 ) 1 D and 3 P, respectively, ionizing the Kr atom, are significantly stronger than the spin-flip ICD processes in which Ar 2+ (3p −3 3d) 1 P and 3 P decay to Ar 2+ (3p −2 ) 3 P and 1 D, respectively