QMC Calculation of the Electronic Correlations in a Fullerene Molecule

Electronic energies are calculated for a Hubbard model on a fullerene molecule ($C_{60}$, $C_{36}$ and $C_{20}$) using projector quantum Monte Carlo (QMC). Calculations are performed to accuracy high enough to determine the pair binding energy for two electrons added to neutral molecule. The method itself is checked against a variety of other quantum Monte Carlo methods as well as exact diagonalization for smaller molecules. We will also show the comparison of our results with the Hund's rule.