In Section IV, we will evaluate the efficacy of two different energy-based screening algorithms. For demonstration purposes, the screening criterion in Eq. ( ) will only be used for n ≥ 3, with all one-and two-body terms evaluated explicitly. (This also allows us to test screening approximations for the higher-order terms in a manner that is uncontaminated by any approximations introduced at the pairwise level.) As test systems, we will use several sets of (H 2 O) N clusters with N = 20, 32, and 64, some of which were taken from previous literature. As in previous work, an ONIOM-style 1,76 supersystem correction is used to correct for long-range electrostatic and polarization interactions.