For the dimers we find that ωB97X-D3BJ or M06-2X with the aug-cc-pVTZ-PP basis set are also generally in agreement for the thermal contributions with maximum differences of around ±1 kcal/mol. For the single-point energy we find that none of the tested DFT methods are adequate, and the popularly used DLPNO-CCSD(T 0 ) method is also inadequate if only triple ζ basis sets are used. However, if it is coupled with a scalar relativistic Hamiltonian, either the Douglass-Kroll-Hess (DKH) or the zeroth order approximation (ZORA), we obtain results in excellent agreement with CCSD(T) with both DKH and ZORA Hamiltonians. We obtain a maximum error of less than 1.1 kcal/mol for DLPNO-CCSD(T 0 ) with DKH and 1.0 kcal/mol for ZORA. We find that ZORA-DLPNO-CCSD(T 0 ) is in excellent agreement with a maximum error of less than 1 kcal/mol compared to DKH-CCSD(T) corrected with the SOC stabilization energy.