We have modeled electron photodetachment spectra of
Cl-H2O and Cl-D2O complexes using 3D
quantum dynamical simulations on the three low-lying electronic
states of the nascent neutral systems. Time-dependent quantum
simulations combined with anionic and neutral stationary state
calculations by imaginary time propagation allowed for
a detailed interpretation of the spectral features in terms of
the underlying dynamics. Due to large differences between the anionic
and neutral potential surfaces, the systems are found after electron
photodetachment primarily high above the dissociation threshold. Nevertheless, pronounced
long-lived resonances are observed, particularly for the lowest neutral state, reflecting the fact
that a significant portion of the excess energy is initially deposited into non-dissociative modes,
i.e. to (hindered) water rotation.
These resonances form bands corresponding  to water rotational states,
with a fine structure due to intermolecular stretch progressions. Comparison is made to experi
mental Zero Electron Kinetic Energy (ZEKE) spectra of
the I-H2O complex, where analogous anharmonic vibrational
progressions have been observed.