If q iA exceeds a tolerance (T CUT MKN , defaulting to 10 -3 for CCSD and 10 -2 for post-CCSD computations, then all the fitting functions centered on atom A are assigned to the DF domain of LMO i. The local DF domain of pair ij is formed from the union of local fitting functions from LMOs i, and j, while the local DF domain of triplet ijk is formed from the union of fitting functions from LMOs i, j, and k.