中文摘要：

用密度泛函理论方法计算了系列含乙硅烷的推拉型有机分子的结构、电子性质和非线性光学（ NLO）性质。该系列分子具有典型的电子供体－共轭桥－电子受体结构，其中乙硅烷的饱和Si Si键嵌入共轭桥，改变了共轭体系的电子性质，导致分子的电子吸收光谱、偶极矩、极化率、超极化率、结晶行为等发生显著改变。在比较研究该系列化合物电子结构的基础上，提出了进一步优化其NLO响应的方法。

英文摘要：

The structure, electronic and nonlinear optical property of a series of push-pull organic molecules with an embedded disilane is studied using density functional theory calculation.These molecules possess a typical electron donor-conjugation path-electron acceptor structure in which the conjugation path is partly blocked by the saturate Si-Si bond of disilane.The conjugation nature of these molecules then varies and leads to significant change in their electronic absorption spectra, dipole moment, polarizability, hyperpolarizability and crystallization.A strategy for optimizing the NLO response of these chromophores is proposed upon a comparative study of their electronic structures.