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Elastic electron scattering with formamide-(H2O)n complexes (n=1, 2): Influence of microsolvation on the π* and σ* resonances 下载免费PDF全文
Kedong Wang 《中国物理 B》2021,30(12):123401-123401
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. 相似文献
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This paper calculates the five most stable conformers of serine with Hartree-Fock theory,density functional theory(B3LYP),M ller-Plesset perturbation theory(MP4(SDQ)) and electron propagation theory with the 6-311++G(2d,2p) basis set.The calculated vertical ionization energies for the valence molecular orbitals of each conformer are in agreement with the experimental data,indicating that a range of molecular conformations would coexist in an equilibrium sample.Information of the five outer valence molecular orbitals for each conformer is explored in coordinate and momentum spaces using dual space analysis to investigate the conformational processes,which are generated from the global minimum conformer Ser1 by rotation of C 2-C 3(Ser4),C 1-C 2(Ser5) and C 1-O 2(Ser2 and Ser3).Orbitals 28a,27a and 26a are identified as the fingerprint orbitals for all the conformational processes. 相似文献
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Electron density distributions of 2-aminoethanol (2AE) and 2-amino-1-propanol (2AP) are calculated in both the coordinate and the momentum spaces using the B3LYP/TZVP method. Using the dual space analysis, molecular orbital signatures of the methyl substituent in 2AP are identified with respect to 2AE. Relaxations of the geometry and the valence orbital in 2AP are found to be due to the insertion of the methyl group. Five orbitals, not four orbitals, are identified as the methyl signatures. They are orbital 5a in the core shell, orbitals 9a and 10a in the inner valence shell, and orbitals 15a and 16a in the outer valence. In the inner valence shell, the attachment of methyl to 2AE causes a splitting of its orbital 8a into orbitals 9a and 10a of 2AP, whereas in the outer valence shell, the methyl group results in the insertion of an additional orbital pair of 15a and 16a. The frontier molecular orbitals 21a, 20a, and 19a are found to have no significant role in the methylation of 2AE. 相似文献
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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. 相似文献
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采用对称性匹配簇/组态相互作用(symmetry adapted cluster-configuration interaction,SAC-CI)方法,在6-311++g**基组水平上优化了甲基乙烯基硅酮分子的前三个单激发态11A″,11A′,21A″的平衡几何结构,比较三个激发态的电荷分布,最高占据轨道,最低空轨道,能隙等结构特性.研究发现,11A′态能隙差最小,电子容易发生跃迁.计算了三个单重激发态相应的振动光谱,得出其振动模式.从甲基乙烯基硅酮分子激发态结构特性,电荷分布,极强位置振动模式等方面分析了其断键机制. 相似文献
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采用从头计算B3LYP,MP3和MP4方法结合Aug-cc-pVDZ基组研究了CH3C(O)OSSOC(O)CH3最稳定的五种构象及其阳离子构型.理论计算了五种稳定构象的转动常数和偶极矩;运用电子传播子理论P3近似方法计算稳定构象外价壳层轨道的电离能,计算结果与光电子能谱实验结果符合的较好.根据构象的相对能量以及理论模拟电离能谱和实验光电子能谱之间的比较,说明在气相光电子能谱实验中至少存在两种构象.与中性构型相比,电离后的五种阳离子构型均发生了明显的结构弛豫,尤
关键词:
构象
电离能
相对能量
光电子能谱 相似文献
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Electron density distributions of 2-aminoethanol (2AE) and 2-amino-l-propanol (2AP) are calculated in both the coordinate and the momentum spaces using the B3LYP/TZVP method. Using the dual space analysis, molecular orbital signatures of the methyl substituent in 2AP are identified with respect to 2AE. Relaxations of the geometry and the valence orbital in 2AP are found to be due to the insertion of the methyl group. Five orbitals, not four orbitals, are identified as the methyl signatures. They are orbital 5a in the core shell, orbitals 9a and 10a in the inner valence shell, and orbitals 15a and 16a in the outer valence. In the inner valence shell, the attachment of methyl to 2AE causes a splitting of its orbital 8a into orbitals 9a and 10a of 2AP, whereas in the outer valence shell, the methyl group results in the insertion of an additional orbital pair of 15a and 16a. The frontier molecular orbitals 21a, 20a, and 19a are found to have no significant role in the methylation of 2AE. 相似文献