Photodissociation spectroscopy of the dysprosium monochloride molecular ion

We have performed a combined experimental and theoretical study of the photodissociation cross section of the molecular ion DyCl⁺. The photodissociation cross section for the photon energy range 35 500 cm⁻¹ to 47 500 cm⁻¹ is measured using an integrated ion trap and time-of-flight mass spectrometer; we observe a broad, asymmetric profile that is peaked near 43 000 cm⁻¹. The theoretical cross section is determined from electronic potentials and transition dipole moments calculated using the relativistic configuration-interaction valence-bond and coupled-cluster methods. The electronic structure of DyCl⁺ is extremely complex due to the presence of multiple open electronic shells, including the 4f¹⁰ configuration. The molecule has nine attractive potentials with ionically bonded electrons and 99 repulsive potentials dissociating to a ground state Dy⁺ ion and Cl atom. We explain the lack of symmetry in the cross section as due to multiple contributions from one-electron-dominated transitions between the vibrational ground state and several resolved repulsive excited states.