外电场作用下SiO电子结构特性研究

在得到SiO分子基态稳定构型的基础上，选用B3P86/6-311++g(d，p)方法优化得到了不同外电场(-0.03—0.03a.u.)下SiO分子基态的稳定电子结构，研究了外电场对SiO分子基态键长、能量、电荷分布、能级分布，能隙及红外光谱的影响规律.结果表明，分子结构与电场呈现强烈的依赖关系，且对电场的方向依赖呈现出不对称性.同时在正向外电场逐渐增大的过程中，SiO分子能隙始终处于减小趋势，占据轨道的电子易于激发至空轨道，因而为研究材料的电致发光机理奠定了一定的理论基础.

Study on the structural properties of SiO molecule under the external electric field

Based on the obtained equilibrium structure for the ground state of SiO molecular, the ground states of SiO molecule under electric fields ranging from -0.03 to 0.03a.u. are optimized using the density functional theory DFT/B3P86 at 6-311++g(d, p)level. The effects of electric fields on the bond length, system energy, charge distribution, energy levels, HOMO-LUMO gaps and the infrared spectrum for the ground states of SiO molecule have been studied. The results show that the molecular geometry is strongly dependent on the field strength and behaves asymmetrically to the directions of the applied electric field. At the same time, the energy gaps between the HOMO and LUMO become closer as the applied electric field along the molecular axis O-Si increases, which shows that the molecule is apt to be excited under specific electric field.