On the pair polarizability of helium

New direct CI calculations of the helium pair polarizability using a gaussian basis set are described. These calculations have been undertaken in an attempt to improve on the previous work in the light of apparent inconsistencies between the computed trace and the polarized Raman spectral lineshape. Good agreement with the spectral model for the anisotropy is obtained. A tabulation of an accurate anisotropy is proposed, together with an analytic model. The calculated trace is not in such good agreement with the trace spectral model. However it is consistent with the experimental value of the second dielectric virial coefficient. The CI contribution is found to be decomposable approximately into a dispersion term and an SCF rescaling part.