  Real-space quantum Monte Carlo is used to calculate the total atomization
energy of benzene. In contrast to orbital-space methods common in quantum
chemistry, real-space methods allow results at near the complete-basis-set
limit to be immediately obtained, all at a computational cost that scales with
the fourth power of system size. We demonstrate this utility using the
moderately sized benzene molecule, obtaining energies that agree with
experiment and previous results from highly accurate composite methods
including HEAT and W2. Due to the low scaling of these algorithms, it opens up
the possibility of addressing systems out of reach of quantum chemical methods.
