中文摘要：

采用密度泛函（DFT）B3LYP方法在6-311＋G基组水平上优化得到了在分子轴方向加不同电场时（TiO2）3团簇分子的基态稳定构型、电偶极矩μ、分子的总能量等,研究了不同外电场下（TiO2）3团簇分子前9个激发态的激发能、跃迁波长等激发特性.分析发现：在有外电场的作用下,分子总能量随着外电场的增加而不断减小,偶极矩随外电场的增加而逐渐增大.其前线轨道的能量也随着外电场的增加而逐渐减小.此外,（TiO2）3团簇分子的激发能、激发波长和振子强度也受到了外电场的影响.

英文摘要：

The ground states parameters,electric dipole moments and the total energies of（TiO2）3cluster under different intense electric fields are studied using density functional theory（DFT）B3LYP based on the 6-311＋G basis set level.The excitation energy,wavelength,oscillator strengths from ground state to the first nine different excited states are calculated in external electric fields,The results show that the energies of the（TiO2）3cluster are proved decreasing with the increasing of external fields,but the dipole moment is contrary.The energies of molecular orbitals decreased with the increasing of external fields.In addition,the electric fields have some effect on the excitation energy,wavelength and oscillator strengths of（TiO2）3cluster.