It is found that in light nuclei it is very important to use a relative kinetic energy operator. This kinetic energy is mass number dependent and contributes in all odd parity (J*,T) channels. In particular it is seen to produce the spurious state exactly at zero energy in the (1−, 0) channel in TDA both in4He and16O. The effect of the relative KE is to decrease the central force attraction and increase the relative importance of the tensor force. The latter is important in RPA. Sussex matrix elements without the hard core are used.
