强外电场作用下BN分子的结构与激发特性  

Molecular structure and excited states for BN under strong electric field

作　　者：曹欣伟[1] 任杨[1] 刘慧[1] 李姝丽[1] 

机构地区：[1]西安文理学院物理与机械电子工程学院,西安710065

出　　处：《物理学报》2014年第4期87-92,共6页Acta Physica Sinica

基　　金：西安市科技计划(批准号:CX12189WL05);西安文理学院大学生创新项目(批准号:201307)资助的课题~~

摘　　要：采用密度泛函理论的B3LYP方法在6-311++g(d.p)水平上优化得到了BN分子轴向加不同外电场时的基态结构参数,包括键长、电偶极矩、电荷分布、前线轨道、红外光谱.计算结果表明,随着正向电场增加,分子结构参数与外电场强度有明显关联,并呈现不对称性.另外,在同样的基组下利用合时密度泛函理论方法研究了外电场对BN分子激发能和振子强度的影响.结果表明,电子跃迁光谱随正向电压的增加而呈现蓝移现象,但振子的强度与电场关联较为复杂,说明光谱强度易受外电场影响.The ground states of BN molecule under different strong electric fields ranging from -0.06 a.u. to 0.06 a.u. are optimized using density functional method B3LYP at 6-311＋＋g（d.p） level. Optimized parameters, dipole moment, charge distribution. HOMO energy, LUMO energy, energy gaps, infrared spectrum are obtained. The result shows that with the increasing of the external electric field, the correlation between molecular structure parameters and the electric field intensity becomes obvious and presents the asymmetry. In addition, TDDFT method at the same level is used to study the influence of external electric field on BN molecular excitation energy and oscillator strength, and the result shows that the electron transition spectrum is blue-shifted with the increase of the external electric field, but the intensity of the vibrator has a more complicated change, showing that the spectral intensity is affected by the electric field.

关 键 词：密度泛函理论 外电场 结构参数 激发态 

分 类 号：O561[理学—原子与分子物理]