For noncovalent clusters, MBE(n) becomes exact when n = N . As such, the relevant benchmark for MBE(n) is a supersystem calculation using the same functional and basis set. Error is defined as the difference between the MBE(n) approximation and the supramolecular benchmark, where the latter has been counterpoisecorrected. Many-body counterpoise corrections for use with MBE(n) have been reported but are not yet implemented in Fragme∩t.