We also integrated the (hyper)polarizability densities illustrated in Fig. in the space of every atom based on the Becke's partition to quantitatively study the contribution of fragments to the major (hyper)polarizability tensorial components . Each molecule is divided into two substructures, C 18 moiety and -(CO) n group, and the corresponding results are plotted in Fig. . According to Fig. , from the perspective of fragment contribution, the two fragments of the precursors C 18 -(CO) n (n = 2, 4, and 6) all make significant contributions to the major tensorial components of (hyper)polarizability of the molecule. Moreover, with the increasing number of the -CO groups in molecule, the contribution of the -(CO) n group to the molecular (hyper)polarizability increases, while the contribution of the C 18 moiety gradually decreases. These results show once again that the introduction of -CO groups in the carbon ring can not only change the optical nonlinearity of the system, but also, more importantly, the (hyper)polarizability of the molecule can be regulated by controlling the number of -CO groups.