In this sense, the energy difference computed between triplet states results in differences ranging from 5.2 to 7.1 kcal/mol with the PBE0-D3 geometry and 3.6 to 4.0 kcal/mol with the TPSSh-D3 geometry with respect to CASPT2 across the LIIC surface. This apparently systematic shift of the whole surface is likely due to differences in the positions of the phenyl rings in the various minimum energy structures. If one is interested in differences on the order of a few kcal/mol, the choice of molecular geometry can matter.