With the aid of the Laplace transform, the canonical expressions of the second-order many-body perturbation corrections to energies and Dyson self-energies are converted into the sum of two 13-dimensional integrals, the 12-dimensional parts of which are evaluated by Monte Carlo integration. Weight functions are identified that are analytically normalizable, are finite and non-negative everywhere, and share the same singularities as the integrands. This algorithm does away with the integral transformation as the hotspot of the usual algorithms, is potentially easily parallelizable, and achieves near linear scaling of cost with system size even for molecules as small as N2 and H2O.

Stochastic evaluation of second-order many-body perturbation corrections to energies and Dyson self-energies

246th National Meeting (2013)

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