含时波包法研究NaH分子的光解截面

Time-dependent wavepacket approach to photodissociation cross section of NaH molecule

采用傅立叶格点哈密顿方法求解含时薛定谔方程、劈裂算符方法传播波函数,计算了NaH分子在三组势能曲线下从初始态X1Σ+(v″=0)跃迁到激发态B1Π的光解截面.研究表明影响光解截面最大值及相应光子能量的关键因素是解离阈能,势能曲线间相对小的平移对计算结果影响不大.应用含时量子力学方法计算光解截面时,车比雪夫多项式方案和劈裂算符方法能够给出基本相同的结果.

By using Fourier grid Hamiltonian method to solve the time-dependent Schr6dinger equation and the split operator scheme for the time propagation of wavepacket, the photodissociation cross sections of Nail molecule from X^1 E^＋ （ v^n = 0） to B ^1Ⅱ have been calculated. Three different sets of the potential - energy curves for X ^1∑^＋ （ v^N= 0） and B ^1Ⅱ states have been used in the calculations. The research shows that the values of the maximum cross section and the corresponding photon energy do not depend much on the minor shift of the potential energy curves but are very sensitive to the dissociation threshold energy. Using time-dependent quantum mechanical method to calculate the photodissociation cross section, the split operator scheme can give basically the same result as Chebyshev polynomial scheme can.