where ∆ECT, ∆EPOL, ∆EDISP, and ∆EELEC stand for the stabilizing energy due to charge transfer effects (inter and intramolecular charge flow between fragments), polarization effects (induced electrostatic), dispersion forces (van der Waals interactions), and Coulombic attractions (classical intermolecular electrostatic), respectively. ∆EPAULI is the energy destabilization due to steric Pauli repulsion. ∆EPREP is the destabilizing geometric/electronic preparation energy required by fragments to reach the complex geometry.