Elastic electron scattering with formamide-(H2O)n complexes (n=1, 2): Influence of microsolvation on the π* and σ* resonances

We report elastic cross sections for low-energy electron scattering with formamide-(H₂O)_n complexes (n=1, 2) in the energy region of 0.01-8 eV. The scattering calculations are performed using the R-matrix method in the static-exchange (SE) approximation. We consider three structures of formamide-H₂O and six structures of formamide-(H₂O)₂ in the present work. Our purpose is to investigate effects of water molecules hydrogen-bonding to formamide. We focus on the influence of microsolvation on the π^* and σ^* resonances of formamide. The scattering result for complexes shows that the position of π^* resonance appears at lower or higher energies in the cluster than in the isolated formamide depending on the complex structure and the water role in the hydrogen bonding. We explain this behavior according to the net charge of the solute. It is found that the microsolvation environment has a substantial effect on the width of π^* resonance. Our results indicate that surrounding water molecules may affect the lifetime of the resonances, and hence the process is driven by the anion state, such as the dissociative electron attachment.     

乙炔分子的低能电子弹性散射研究

本文采用R矩阵方法研究低能电子与乙炔分子的弹性散射截面及其动力学过程.研究采用静态交换势模型(SE)和静态交换加极化势模型(SEP)两种方法.结果显示当前SEP模型预测的弹性散射截面与已有的实验值和理论结果符合的很好.SE模型预测了一个位于4.75 eV,宽度为3.0 eV的π形状共振态.该共振态在SEP模型中的位置降低为2.65 eV,宽度为1.5 eV.它来自B_(2g)和B_(3g)对称性贡献,理论预测共振态位置与实验值符合的很好.我们讨论了考虑不同的虚轨道对共振态的影响,说明预测精确的共振态的位置需要准确的处理极化效应.基于SEP模型得到的K矩阵元,我们使用POLYDCS代码计算的散射微分截面(DCS),和实验值符合的较好.除此之外,我们还报道了2 eV时转动分辨的态-态微分截面.     

BeCl_2分子的低能电子弹性散射研究

基于R矩阵理论方法,通过构建BeCl_2分子的静态交换势模型(SE),静态交换加极化势模型(SEP)和密耦合模型(CC),在0-10 eV能量范围内首次研究了低能电子与BeCl_2分子的散射动力学过程,预测了弹性散射积分截面,并在三种模型中分别发现一个来自B_(2u)和B_(3u)对称性贡献的势形共振态.讨论了这些共振态随着极化效应的变化,获得了收敛的截面和共振态结果.进一步使用POLYDCS程序首次计算了电子与BeCl_2分子的散射微分截面(DCS)以及动量转移截面(MTCS).当前研究结果将为天体物理和等离子体物理提供重要的截面数据.