by applying MBE(n) consistently to E P:L and E P . A large number of subsystem calculations cancel in eq. 6 and can be eliminated a priori, as described elsewhere. In principle, eq. 6 should be combined with counterpoise correction to eliminate basis-set superposition error (BSSE), which can be quite large for sizable proteinligand models, especially if double-ζ basis sets are used. Many-body counterpoise corrections that are consistent order-by-order with MBE(n) have been developed for this purpose but are not yet available in Fragme∩t. As a result, and because we are interested in demonstrating that our protocols are robust in large basis sets, we opt to push our calculations to the complete basis-set (CBS) limit using triple-and even quadruple-ζ basis sets.