The previous section highlights why a multireference method is important to obtain the proper shape of the PES; however, one might wonder how well the traditional approach, to optimize the geometry with DFT and perform a single-point calculation to characterize the electronic structure with XMS-CASPT2, would perform. To test this approach, the TPSSh-D3 and PBE0-D3 molecular geometry is compared with the structure from XMS-CASPT2.