碘代乙烷分子光解离的自旋轨道从头计算理论研究

摘要

The potential energy curves of C2H5I correlated to the dissociation limits of I(2P3/2) and I*(2P1/2) atom are calculated using the second-order spin-orbit multiconfiguration quasidegenerate perturbation theory (SO-MCQDPT).The potential energy curves of C2H5I indicate that all the low-excited states are repulsive states except for the 3Q0+ (33A″) state,which has a shallow minimum of 337 cm-1 at RC-I=0.346 nm.The calculated vertical excitation energies of 3Q0+ (33A″) and 1Q1 (21A’, 11A″) for C2H5I indicate that the wavelength range of the A-band absorption spectrum mainly lies between 33478 cm-1 and 44150 cm-1 ,i.e., between 226nm and 299nm.This result is in good agreement with experimental measurement (243 nm～285 nm).%采用从头计算二阶-自旋轨道多组态准闹并微扰理论计算了碘代乙烷C2H5I分子与基态I(2P3/2)原子和哎发态I*(2P1/2)原子解离限相关联的势能曲线.C2H5I分子的势能曲线表明除了3Q0+(33A")态外几个低激发态都为排斥态,3Q0+电子态在Rc-1=0.346 nm处有337 cm-1的一个浅势阱.3Q0+(33A")和1Q1(21A',11A")电子态的垂直激发能计算表明C2H5I分子的A带吸收谱的波长区间为33478 cm-1～44150 cm-1(226 nm～299 nm),这与实验给出的(243 nm～285 nm)波长区间吻合较好.