The application of D3(BJ) and D4 dispersion corrections shows significantly reduced MADs across all tested functionals, excluding ωB2(GP-)PLYP, with larger reductions observed for D e than for r e . However, the improvement to excimer binding by the tested dispersion corrections shown through this reduction in MADs is not predictable. While dispersion-uncorrected functionals yield errors due to underestimation of D e and overestimation of r e , dispersion corrections under or overcorrect depending on the system and functional. D4 and D3(BJ) yield similar D e MADs in the order of 1.96-6.58 kcal/mol and 1.48-6.59 kcal/mol, respectively. For the same underlying functional, the two iterations of DFT-D yield comparable MADs where differences between D4 and D3(BJ) MADs do not exceed 0.03 Å or 1.16 kcal/mol, with the exception of B2GP-PLYP where D4 gives considerably higher D e deviations than D3(BJ).