A combined ab initio and Franck-Condon simulation study of the photodetachment spectrum of the ClO2- anion

► We present an analytical expression to calculate the two-dimensional Franck-Condon integrals. ► The electron affinity of ClO2 are calculated at the CCSD(T) CBS limit. ► The photoelectron spectrum of ClO2- are simulated and the role of Duschinsky effects and hot bands are clarified. ► The equilibrium geometry of ClO2- are deduced in the spectral simulation.