Much of our prescreening to classify pairs in the DLPNO-CCSD algorithm is derived from the original work of Valeev, Neese, and coworkers. We first screen out the dipole pairs based on the T CUT DO ij and T CUT PRE cutoffs, the overlap and energy criteria used to ensure that LMOs i and j are non-overlapping. Next, we determine the semicanonical MP2 pairs as all non-dipole pairs with an energy contribution less than T CUT PAIRS MP2 .