The geometries, energies, and various electronic properties of the allenes CH2= C= CH2, CH,= C= CHF, CHF= C= CHF, CH2= C= CF2, CHF= C= CF2, CF2= C= CF2 and the acetylenes CH3C= CH, CH3CrCF, CF3C= CH, and CF3C= CF have been calculated at the SCF level with a double-{basis set augmented by polarization functions on carbon. Final energies and properties were calculated with a fully polarized double-{basis set. Final ...