利用密度泛函BLYP方法优化得到了TiO分子的稳定构型,并计算了TiO分子基态在外场作用下前线轨道变化情况,然后利用杂化组态相互作用CIS-DFT方法,比较了TiO分子在外电场下的激发特性.结果表明,在一定的电场范围内,随着电场的增大,α轨道的最高占据轨道与最低空轨道能隙逐渐变小,β轨道能隙逐渐变大,同时可跃迁的低激发态跃迁波长随电场的增大而变长,高激发态波长变化相对复杂,且基态跃迁至激发态的耦合强度随外电场的增大而加强.
The present paper is devoted to the calculating of transition wavelengths,oscillator strength,Einstein An0 and B0n coefficients of titanium monoxide molecule from ground state to the first six different excited states by employing the density function theory BLYP and the single substitute configuration interaction approach with basis set 6-311+ + G**.The excited states of titanium monoxide molecule under different external electric fields are also investigated.It is shown that the α HOMO-LUMO gaps become smaller and the electrons of the occupied orbital tend to the virtual orbital as the external electric field intensity increases,and the β HOMO-LOMO gaps become bigger,while the variation in excitation wavelength of high-excited states turns more complicated than that of low-excited states,and the coupling strengths of excited states increase with external electric field increasing.