He-HBr体系各向异性势及非弹性散射截面的理论研究

首先用BFW势函数形式拟合在CCSD(T)/aug-cc-pVQZ理论水平下计算的He-HBr相互作用能数据,得到了He原子与HBr分子各向异性势;并与ESMSV势进行比较,验证了拟合势的可靠性;然后采用公认的精确度较高的CC近似方法计算了He-HBr碰撞体系能量在150meV下He原子和HBr分子碰撞的转动激发微分截面和分波截面,总结了该碰撞体系非弹性散射截面的变化规律.研究表明:①拟合势较好地描述了He-HBr系统相互作用的各向异性特征;利用碰撞体系分子间势的量子化学从头计算结果,可解决势能参数难以确定的问题.②低激发态被激发的几率要远远大于高激发态被激发的几率;激发态越高,大角散射的几率越大.③尾部效应仅在低激发态中产生,高激发态不产生尾部效应.     

Murrell-Sorbie势能参数与双原子分子光谱数据的关系研究

研究了Murrell-Sorbie势能参数与双原子分子光谱数据的关系.根据光谱数据编程计算了卤化氢分子的力常数和Murrell-Sorbie势能参数.反过来,运用ab initio和非线性最小二乘法拟合出了HF分子的Murrell-Sorbie势能函数和势能参数;并由此计算了HF分子的光谱数据,与实验光谱数据符合较好.这对难以获得实验光谱数据的双原子分子和离子的动力学研究有一定的参考价值.     

Synchrotron radiation VUV double photoionization of some small molecules

The VUV double photoionizations of small molecules (NO,CO,CO2 ,CS2 ,OSC and NH3 ) were investigated with photoionization mass spectroscopy using synchrotron radiation. The double ionization energies of molecules were determined with photoionization efficiency spectroscopy. The total energies of these molecules and their parent dications (NO2+ ,CO2+ ,CO2+2 ,CS2+2 ,OSC2+ and NH2+3 ) were calculated using the Gaussian 03 program and Gaussian 2 calculations. Then,the adiabatic double ionization energies of the molecules were predicated by using high accuracy energy mode. The experimental double ionization energies of these small molecules were all in reasonable agreement with their respective calculated adiabatic double ionization energies. The mechanisms of double photoionization of these molecules were discussed based on a comparison of our experimental results with those predicted theoretically. The equilibrium geometries and harmonic vibrational frequencies of molecules and their parent dications were calculated by using the MP2 (full) method. The differences in configurations between these molecules and their parent dications were also discussed on the basis of theoretical calculations.     

He-HF（DF，TF）碰撞体系分波截面的理论计算

运用质心变换-拟合方法,使用Murrell-Sorbie势能函数拟合在对称性匹配微扰理论下精确计算He-HF体系的相互作用能数据,得到了He原子与同位素分子HF（DF,TF）复合物的相互作用势的解析形式.完成了入射He原子能量从30 meV至120 meV时,He-HF（DF,TF）碰撞体系分波截面的密耦计算,获得了分波截面等信息,进一步讨论了分波截面的变化趋势及特征,并确定了He-HF（DF,TF）碰撞体系开始产生弹性和非弹性散射的有效相互作用范围. 关键词： He-HF（DF TF）复合物 密耦近似 分波截面 质心偏移     

He-HI碰撞的转动激发分波截面

基于作者所发展的分子间相互作用势,采用密耦方法计算了入射He原子能量分别为40,75和100　meV时与HI分子碰撞的弹性和非弹性分波截面.研究表明：激发分波截面比弹性分波截面收敛得快;激发态越高,激发分波截面收敛得越快;能量越高,激发分波截面收敛得越慢. 关键词： 分波截面 密耦方法 He-HI复合物     

Ne-HF体系的相互作用势及散射截面的密耦计算

利用非线性最小二乘法拟合在CCSD(T)/aug-cc-pVQZ理论水平下计算的相互作用能,得到了基态Ne-HF体系相互作用势的解析表达式.基于拟合的CCSD(T)势,通过密耦计算得到了入射能量分别为60,75,100和150meV 时,Ne-HF散射的微分截面和分波截面,详细讨论了散射截面随能量的变化趋势以及态-态激发截面对总非弹性散射截面的影响. 关键词： 相互作用势 散射截面 密耦计算 Ne-HF体系     

Isotope effect in collision between heliumatom and hydrogen bromide molecule

The anisotropic potential developed in our previous research and the close-coupling method are applied to the HBr-3He （4He, 5He, 6He, 7He） system, and the partial cross sections （PCSs） at the incident energy of 60meV are calculated. Based on the calculations, the influences of the isotope helium atom on PCSs are discussed in detail. The results show that the excitation PCSs converge faster than the elastic PCSs for the collision energy and the systems considered here. Also the excitation PCSs converge more rapidly for the high-excited states. The tail effect is present only in elastic scattering and low-exclted states but not in high-excited states. With the increase of reduced mass of the collision system, the converging speed of the elastic and excitation PCSs slows down, and the tail effect goes up.     

He-HF碰撞体系相互作用势及散射截面的理论研究

首先以与散射数据和实验结果符合较好的BFW势为依据,拟合了He-HF碰撞体系相互作用的ESMSV势,并与其它势进行比较,验证了拟合势的可靠性;然后采用密耦近似方法计算了不同势下He原子和基态HF分子碰撞的散射截面,并将计算结果与散射实验数据作了比较;最后研究了该碰撞体系散射截面的变化规律.研究表明:拟合势能较好地描述He-HF系统相互作用的基本特征.     

He-HI复合物势能面及微分散射截面的理论研究

采用超分子单双迭代(包括非迭代三重激发)耦合簇理论CCSD(T)方法和由键函数3s3p2d1f组成的大基组, 计算得到了基态He-HI复合物相互作用的全程势能面. 该势能面上存在2个势阱, 分别对应于线性He-I-H和He-H-I构型, 势阱深度分别为4.473和2.996meV, He原子到HI分子质心的距离R分别为0.363和0.442nm. 使用Barker, Fisher和Watts提出的BFW势函数拟合计算得到的相互作用能数据, 获得了He原子与HI分子相互作用势的解析表达式. 在 关键词： He-HI复合物 势能面 微分散射截面     

He-HF振转相互作用势及其散射动力学

本文拟合在对称性匹配微扰理论(SAPT)水平下计算的He-HF范德瓦耳斯复合物的相互作用能,获得了He-HF解析振转相互作用势.这个势能面(HF分子的键长取平衡核间距0.091696nm)上存在两个线性极小,即He-HF和He-FH构型,He原子到HF质心的距离分别为0.319nm和0.296nm,键能分别为-38.33cm-1和-33.62cm-1.在此势能面上使用密耦方法计算了碰撞能量分别为480,1000,1500,2000和2500cm-1时的积分截面和分波截面,发现振转相互作用势的精确性不仅表现在它与Lovejoy等人提出的经验势符合较好,而且还复制了碰撞能量为480cm-1时的实验态-态积分截面.在此基础上,进一步讨论了分波截面随碰撞参数的变化趋势以及振转势能面对弹性和非弹性分波截面的影响.