Comment on "An exact quantum Monte Carlo calculation of the helium-helium intermolecular potential" [J. Chem. Phys. 115, 4546 (2001)]

We report a further reduction in the statistical error for “exact” quantum Monte Carlo calculations for the potential energy of interaction of two helium atoms. For the equilibrium internuclear distance of 5.6 bohr, the calculated electronic energy is −5.807 483 583±0.000 000 016 hartrees and the corresponding well depth is (ε/k) 10.995±0.005 K.