  We develop and implement a Gaussian approach to calculate partial
cross-sections and asymmetry parameters for molecular photoionization. Optimal
sets of complex Gaussian-type orbitals (cGTOs) are first obtained by non-linear
optimization, to best fit sets of Coulomb or distorted continuum wave functions
for relevant orbital quantum numbers. This allows us to represent the radial
wavefunction for the outgoing electron with accurate cGTO expansions. Within a
time-independent partial wave approach, we show that all the necessary
transition integrals become analytical, in both length and velocity gauges,
thus facilitating the numerical evaluation of photoionization observables.
Illustrative results, presented for NH3 and H2O within a one-active-electron
monocentric model, validate numerically the proposed strategy based on a
complex Gaussian representation of continuum states.
