When using a 3c method to refine an ensemble before reoptimization using DFT, it would be helpful for the binding energies and geometries given by the 3c method to be close to those given by DFT. Equally importantly, the energetic ordering should remain consistent, such that conformers which are low in energy according to the 3c method are also low in energy when using DFT. In other words, the shape of the potential energy surface should be similar in both the 3c method and in full DFT. Thus, prospective methods were evaluated both for absolute binding energies and for relative binding energies, as compared to the published ωB97X-V/def2-TZVP values, at the published geometries. Thirdly, efficient methods are highly desirable for screening, so the methods were compared in terms of computer time required, measured in core-seconds. All computations in this section were performed on a single core, for ease of comparison.