We have performed Hartree-Fock ab initio calculations on GaH3-H2O, GaF-H2O, and GaCl3-H2O to determine minimum-energy geometries, vibrational frequencies, and binding energies between the two molecular moieties. Qualitatively, the structures and binding energies were very similar to those for the corresponding aluminum complexes, and the binding energy was much larger than that for BF3-H2O. The potential energy surface as determined by rotation about the Ga-O bond shows some unusual features An estimate of the basis set superposition error is also presented.