In this section, we analyse the influence of FE on the description of excimer binding by global hybrids. This analysis was performed by varying percentages of FE, between 0 and 75%, for two underlying exchange-correlation (XC) approximations, PBE and BLYP. The resulting functionals of varied FE are detailed in Table . PBE and BLYP were chosen as they are the XC approximations behind many popular (double-)hybrids, and as using two different approximations may help us to better indicate the indi- vidual influence of FE or the underlying XC expression. The functionals are analysed through their ability to recover the minimum of the dissociation curve of each excimer which can be separated into the equilibrium distance (r e ) between the two monomers and the stability of the dimers represented by the dissociation energy (D e ). The ability of each method to describe these parameters is assessed by quantitative comparison to those calculated with our SCS-CC2/CBS (3,4) references by use of signed percentage error: