A new method, reduced Hamiltonian interpolation (RHI) combines dimensional interpolation with ideas from N-representability. This has provided promising results for a system of spinless bosons, predicting over 99% of the correlation energy. Current efforts are directed towards applying this methodology to more realistic interaction potentials in Bose-Einstein condensates and treating correlations of fermions.
Latest (and first!) Reference:
"Boson Correlation Energies from Reduced Hamiltonian Interpolation"
David A. Mazziotti and Dudley Herschbach
Physical Review Letters, Volume 83, pp. 5185-5189