We first examine linear alkanes C n H 2n+2 , as considered recently using an alternative local-orbital approxi- mation to MP2. 106 That work demonstrated a constant fractional error in the correlation energy as a function of the chain length n, meaning that a consistent fraction of the (size-extensive) correlation energy is recovered. The same is true within the DLPNO approximation as demonstrated by results in Fig. , which plots the DLPNO error per carbon atom as a function of n. Sizeextensivity implies that the canonical result is a constant for large systems, and that behavior is indeed observed for each set of PNO thresholds. Loose thresholds require a somewhat longer carbon chain to reach the asymptotic result.