To further evaluate the method, absorption energies of para-nitroaniline were computed in vacuum, cyclohexane, toluene, dichloroethane, acetonitrile, and water. The reference SCF calculations were performed using a CAS(16e,12o) active space, consisting of ten π orbitals and two n O orbitals (see Figure in the Supporting Information). The first five states were equally averaged (SA5). Geometry optimizations and absorption energy calculations were performed at the CASSCF, XMS-CASPT2, and RMS-CASPT2 levels using the ANO-RCC-VTZP basis set. CASPT2 calculations were conducted with an imaginary level shift of 0.2i.