with T 1 , T 2 , and T 3 being the one-, two-, and three-electron excitation operators, respectively. For coupled-cluster theory, relative energy errors of 1 kcal mol -1 or less are typically achievable only when triples excitations are considered. Historically, this required an exact treatment of triples excitations using CCSDT, a perturbative treatment using the CCSD(T) method, or through various simplifications of the full CCSDT method: CCn, nCC, and CCSDT-n methods. CCSD(T) has become known as the "gold standard" method in quantum chemistry, due to its decent accuracy relative to its computational expense, and there have been a myriad of approximations devised to reduce the cost of the CCSD(T) method. These include but but are not limited to density-fitting (DF)/resolution of the identity (RI), rank reduction (RR), tensor hypercontraction (THC), as well as localized orbitals. The latter include, in particular, the domain-based local pair natural orbital (DLPNO) approach of Neese and coworkers. Localized orbital approaches are also known as local correlation methods, and these methods are most popular due to its asymptotic linear scaling cost, and its tractability for larger molecules. With these local correlation methods, computations have been performed on a linear alkane containing 350 carbons in the def2-TZVPP basis (1252 atoms, 20678 basis functions) through the DLPNO-CCSD(T 0 ) algorithm in ORCA, while the DLPNO-CCSD(T) algorithm, available in both ORCA and Psi4, has been performed on a whole insulin peptide in the def2-SV(P) basis (787 atoms, 6458 basis functions) through (T). These system sizes are much larger than what can be computed with canonical CCSD(T) on a typical lab workstation.