The ground-state electronic structures of K3V(ox)(3)center dot 3H(2)O, Na3V(ox)(3)center dot 5H(2)O, and NaMgAl1-xVx(ox)(3)center dot 9H(2)O (0 < X <= 1, ox = C2O42-) have been studied by Fourier-transform electronic absorption and inelastic neutron scattering spectroscopies. High-resolution absorption spectra of the (3)Gamma(t(2g)(2)) -> (1)Gamma(t(2g)(2)) spin-forbidden electronic origins and inelastic neutron scattering measurements of the pseudo-octahedral [V(ox)(3)](3-) complex anion below 30 K exhibit both axial and rhombic components to the zero-field-splittings (ZFSs). Analysis of the ground-state US using the conventional S = 1 spin Hamiltonian reveals that the axial ZFS component changes sign from positive values for K3V(ox)(3)center dot 3H(2)O (D approximate to +5.3 cm(-1)) and Na3V(ox)(3)center dot 5H(2)O (D approximate to +7.2 cm(-1)) to negative values for NaMgAl1-x center dot V-x(ox)(3)center dot 9H(2)O (D approximate to -9.8 cm(-1) for x = 0.013, and D approximate to -12.7 cm(-1) for x = 1) with an additional rhombic component, IEI, that varies between similar to 0.8 and similar to 2 cm(-1). On the basis of existing crystallographic data, this phenomenon can be identified as due to variations in the axial and rhombic ligand fields resulting from outer-sphere H-bonding between crystalline water molecules and the oxalate ligands. Spectroscopic evidence of a crystallographic phase change is also observed for K3V(ox)(3)center dot 3Y(2)O (Y = H or D) with three distinct lattice sites below 30 K, each with a unique ground-state electronic structure.