To further improve the pyrenyl-contained derivatives two-photon absorption (TPA) and third-order nonlinear optical (NLO) properties, three steps of optimization are employed based on experimental molecule PCVS-B: heteroatomic substitution, exchanging the position of double bonds and adding a branch. The contributions of π electrons to localized orbital locators and Mayer bond orders (LOL-π and I_AB^π) show that the second step can enhance the chemical interaction between pyrenyl and the branched-chain. Two visual methods of charge density difference (CDD) and transition density matrix (TDM) are combined to intuitively analyze the intramolecular charge transfer (ICT) process of one (two) photon absorption; results show that both following two steps can increase the degree of ICT on the conjugated plane of the pyrenyl. The sum over state (SOS) model was used to find out the dominant two-photon transition process. The difference between the dipole moments obtained by the McRae equation is applied to the three-state model, revealing the inherent law of the second static hyperpolarizability.

为了进一步提高the基衍生物的双光子吸收（TPA）和三阶非线性光学（NLO）性能，基于实验分子PCVS-B，采用了三个优化步骤：杂原子取代，交换双键和添加一个分支。π电子的局部轨道定位器和Mayer键级（LOL-π和贡献我_AB ^π）表明第二步可以增强pyr烯和支链之间的化学相互作用。结合了两种可视的电荷密度差（CDD）和跃迁密度矩阵（TDM）方法，可以直观地分析一（二）个光子吸收的分子内电荷转移（ICT）过程。结果表明，随后的两个步骤均可提高increase烯共轭面上的ICT程度。状态总和（SOS）模型用于找出主导的两光子跃迁过程。通过McRae方程获得的偶极矩之间的差异应用于三态模型，揭示了第二个静态超极化率的内在规律。