[en] The electronic structure, mechanical and magnetic properties of Ni₃Al, Ni₃Ga and Ni₃In have been studied by spin-density functional theory with generalized gradient approximation and also by X-ray absorption near-edge spectra (XANES) at the Ni, Ga K edges. The calculated lattice constants and bulk modulii are in good agreement with experiments. All three compounds have a similar calculated density of states (DOS) spectrum and are predicted to be a weak ferromagnet. The measured Ni(Ga) K-edge XANES are well explained by the theoretical XANES and unoccupied Ni(Ga)-p DOS, suggesting that XANES is a useful probe of the electronic structure of the intermetallics