On the T-shaped structures of the benzene dimer

We report the fully relaxed geometries of two distorted T-shaped benzene dimer structures optimized at the RI-MP2/aug-cc-pVTZ level of theory. At both the extrapolated RI-MP2/aug-cc-pV(TQ)Z level and the ΔCCSD(T)/6-311+G(2df,p) approximation to the CCSD(T)/CBS limit, these configurations were found to be lower in energy than the conventionally accepted C2v T-shaped structure.