SiTe分子激发态光谱性质的理论研究

Theoretical study on the spectral properties of SiTe molecule excited states

采用多参考组态相互作用(MRCI)的方法研究了Si Te分子的电子结构,获得18个Λ-S态的势能曲线.基于势能曲线(PECs)通过数值积分方法获得电子态的光谱常数.计算Si Te分子的电偶极矩(PDMs)并分析电子组态的变化对电偶极矩的影响.此外,计算得到的势能曲线表明,11Π和13Π态与附近的5个电子态(13Σ^(+),13Δ,11Σ^(-),13Σ^(-),11Δ)在16500~27400 cm^(-1)的能量区域内密集分布,邻近的电子态对13Π态有明显的扰动作用.通过11Π和13Π态的自旋-轨道耦合矩阵元,分析电子组态与自旋-轨道耦合矩阵元的关系.最后,计算了SiT e分子21Σ^(+)-X1Σ^(+),13Π-13Δ,11Π-X1Σ^(+),13Π-13Σ^(-)和13^(+)Σ^(-)13Π的跃迁偶极矩(TDM)以及11Π-X1Σ^(+)和21Σ^(+)-X1Σ^(+)的辐射寿命.

The electronic structure of SiTe molecules is studied by multi-reference configuration interaction(MRCI)method,and the potential energy curves of 18Λ-S states are obtained.The spectroscopic constants of electronic states are obtained by numerical integration method based on potential energy curve(PECs).The electric dipole momen(tPDMs)of SiTe molecule was calculated and the effect of the change of electronic configuration on the PDMS was analyzed.In addition,the calculated potential energy curve shows that the 1~1Πand 1~3Πstates and the five nearby electron states(1~3Σ^(+),1~3Δ,1~1Σ^(-),1~3Σ^(-),1~1Δ)are densely distributed in the energy region of 16500~27400 cm~(-1),and the neighboring electron states have a significant perturbation effect on the1~3Πstate.The relationship between electron configuration and the spin-orbit coupling~1 matrix elements of 1~1Πand 1~3Πand states is analyzed.Finally,the transition dipole moment(TDM)of2~1Σ^(+)-X~1Σ^(+),1~3Π-1~3Δ,1~1Π-X~1Σ^(+),1~3Π-1~3Σ^(-)and 1~3Σ^(+)-1~3Πand the radiation lifetimes of 1~1Π-X~1Σ^(+)and 2~1Σ^(+)-X~1Σ^(+)are calculated.