  We have investigated decorrelation of samples in Quantum Monte Carlo (QMC)
ground-state energy calculations for large Li and H$_{2}$O nanoclusters.
Binning data as a way of eliminating statistical correlations, as is the common
practice, is found to become increasingly impractical as the system size grows.
We demonstrate nevertheless that it is possible to perform accurate energy
calculations - without decorrelating samples - by exploiting the scaling of the
integrated autocorrelation time $\tau$ as a function of the number of electrons
in the system.
