The molecular dipole polarizability α (referred to simply as polarizability in the manuscript), on the other hand, describes the dipolar response of a molecule to an external electric field, becoming a key quantity for understanding intra-and intermolecular interactions (e.g., dispersion interactions, substituent and solvent effects as well as supramolecular structure formation) and for determining spectroscopic properties of molecules (Raman and sum frequency spectroscopy) . These features make both polarizability and HOMO-LUMO gap essential in the derivation of structure-property/property-property relationships and, consequently, in the development of design strategies for molecules with a targeted array of QM properties for applications such as molecular dyes , optoelectronic devices , molecular junctions , heterogeneous catalysts and materials for non-linear optics .