  We investigated the effect of deuteration on the vibrational ground state of
the hydrated hydroxide anion using a nine-dimensional quantum dynamical model
for the case of J=0. The propagation of the nuclear wave function has been
performed with the multi-configuration time-dependent Hartree method which
yielded zero-point energies for the normal and fully deuterated species in
quantitative agreement with previous diffusion Monte Carlo calculations.
According to the zero-point energy the isotopomers having the hydrogen atom in
the bridging position are more stable by about 1 kJ/mol as compared to the
deuterium case. This holds irrespective of the deuteration state of the two OH
groups. We also report the secondary geometric H/D isotope effect on the O--O
distance which amounts to an elongation of about 0.005 A for the symmetric
isotopomers and 0.009 A in the asymmetric case. Finally, we explore the
isotopomer sensitivity of the ground state tunneling splitting due to the
torsional motion of the two OH groups.
