The effective correlation theory for liquid 3He

It is shown that when the antisymmetry of liquid 3He is treated with the effective correlation theory of Lado, the optimal HNC solution gives very good agreement with the optimal FHNC theory when in the latter the long wave length properties due to Fermi cancellations are treated properly. When in addition elementary diagrams are calculated with the Pade approximation, ground state energies are obtained that agree quite well with the Monte-Carlo results of Ceperley, Chester and Kalos and Levesque, especially at low densities. In addition the contribution of the three-body factors in the variational wave function is calculated. The expectation value of the ground state energy is found to be -1.62+-0.15 K at a saturation density 0.015+-0.001 A-3. (Auth.)