  We extend a previously developed model for the Stark resonances of the water
molecule. The method employs a partial-wave expansion of the single-particle
orbitals using spherical harmonics. To find the resonance positions and decay
rates, we use the exterior complex scaling approach which involves the analytic
continuation of the radial variable into the complex plane and yields a
non-hermitian Hamiltonian matrix. The real part of the eigenvalues provides the
resonance positions (and thus the Stark shifts), while the imaginary parts
$-\Gamma/2$ are related to the decay rates $\Gamma$, i.e., the full-widths at
half-maximum of the Breit-Wigner resonances. We focus on the three outermost
(valence) orbitals, as they are dominating the ionization process. We find that
for forces directed in the three Cartesian co-ordinates, the fastest ionizing
orbital always displays a non-monotonic Stark shift. For the case of fields
along the molecular axis we also compare results as a function of the number of
spherical harmonics included ($\ell_{\max}=3,4$). We also compare our results
to the total molecular Stark shifts for the Hartree-Fock and coupled cluster
methods.
