Low-Energy Electron and Positron Scattering by Lysine: Cross Sections and Theoretical Insights into Possible DEA Pathways.

IF 2.8 2区 化学 Q3 CHEMISTRY, PHYSICAL
Cesar A do Amaral, Raul V B Morás, Giseli M Moreira, Sergio d'Almeida Sanchez, Alessandra Souza Barbosa
{"title":"Low-Energy Electron and Positron Scattering by Lysine: Cross Sections and Theoretical Insights into Possible DEA Pathways.","authors":"Cesar A do Amaral, Raul V B Morás, Giseli M Moreira, Sergio d'Almeida Sanchez, Alessandra Souza Barbosa","doi":"10.1021/acs.jpca.5c05601","DOIUrl":null,"url":null,"abstract":"<p><p>We report a theoretical investigation of low-energy electron and positron scattering by the lysine molecule. The calculations were performed using the Schwinger multichannel method with different levels of approximation for each projectile. The static-exchange (SE) and static-exchange plus polarization (SEP) approximations were used for electrons, while the static plus polarization (SP) approximation was used for positrons. Our results for electron scattering show a π* resonance centered at 3.95 eV for SE and 2.73 eV for SEP in the integral cross section, as well as a large structure around 11.0 eV for SE and 9.0 eV for SEP, which may be associated with overlapping σ* resonances. For comparison purposes, since there are no theoretical or experimental cross sections available in the literature, a semiempirical relation was employed to estimate the value of the π* resonance. We also compared the results obtained for electron and positron scattering, showing similar behavior at very low energy due to the dipole interaction and approximately the same order of magnitude from 2 to 6 eV. Differential cross sections for both projectiles also exhibit the same dominant wave pattern. To investigate the connection between the resonance and the dissociative electron attachment (DEA), we calculated threshold energies for hydrogen loss from different sites in the molecule, identifying a low-energy channel (1.85 eV) consistent with previous DEA studies on similar systems. Furthermore, excited electronic states of lysine were obtained by using time-dependent density functional theory (TDDFT), providing additional insight into possible Feshbach-type DEA pathways. These results represent the first theoretical study of scattering processes involving electrons and positrons with lysine and offer a foundation for future experimental and computational investigations.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.8000,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Journal of Physical Chemistry A","FirstCategoryId":"1","ListUrlMain":"https://doi.org/10.1021/acs.jpca.5c05601","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0

Abstract

We report a theoretical investigation of low-energy electron and positron scattering by the lysine molecule. The calculations were performed using the Schwinger multichannel method with different levels of approximation for each projectile. The static-exchange (SE) and static-exchange plus polarization (SEP) approximations were used for electrons, while the static plus polarization (SP) approximation was used for positrons. Our results for electron scattering show a π* resonance centered at 3.95 eV for SE and 2.73 eV for SEP in the integral cross section, as well as a large structure around 11.0 eV for SE and 9.0 eV for SEP, which may be associated with overlapping σ* resonances. For comparison purposes, since there are no theoretical or experimental cross sections available in the literature, a semiempirical relation was employed to estimate the value of the π* resonance. We also compared the results obtained for electron and positron scattering, showing similar behavior at very low energy due to the dipole interaction and approximately the same order of magnitude from 2 to 6 eV. Differential cross sections for both projectiles also exhibit the same dominant wave pattern. To investigate the connection between the resonance and the dissociative electron attachment (DEA), we calculated threshold energies for hydrogen loss from different sites in the molecule, identifying a low-energy channel (1.85 eV) consistent with previous DEA studies on similar systems. Furthermore, excited electronic states of lysine were obtained by using time-dependent density functional theory (TDDFT), providing additional insight into possible Feshbach-type DEA pathways. These results represent the first theoretical study of scattering processes involving electrons and positrons with lysine and offer a foundation for future experimental and computational investigations.

赖氨酸的低能电子和正电子散射:可能的DEA途径的截面和理论见解。
我们报道了赖氨酸分子对低能电子和正电子散射的理论研究。采用Schwinger多通道方法对每个弹丸进行了不同程度的近似计算。电子采用静态交换(SE)和静态交换+极化(SEP)近似,正电子采用静态+极化(SP)近似。电子散射结果表明,在积分截面上,SE和SEP存在一个以3.95 eV和2.73 eV为中心的π*共振,SE和SEP存在一个以11.0 eV和9.0 eV为中心的大结构,这可能与重叠的σ*共振有关。为了比较,由于文献中没有理论或实验截面,因此采用半经验关系来估计π*共振的值。我们还比较了电子和正电子散射的结果,由于偶极子相互作用,在非常低的能量下表现出相似的行为,并且在2到6 eV之间大约相同的数量级。两种射弹的微分截面也表现出相同的主导波型。为了研究共振与解离电子附着(DEA)之间的联系,我们计算了分子中不同位点氢损失的阈值能量,确定了一个低能量通道(1.85 eV),与之前在类似系统中的DEA研究一致。此外,利用时间依赖密度泛函理论(TDDFT)获得了赖氨酸的激发态,为可能的feshbach型DEA途径提供了额外的见解。这些结果代表了电子和正电子与赖氨酸散射过程的第一个理论研究,并为未来的实验和计算研究奠定了基础。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
The Journal of Physical Chemistry A
The Journal of Physical Chemistry A 化学-物理:原子、分子和化学物理
CiteScore
5.20
自引率
10.30%
发文量
922
审稿时长
1.3 months
期刊介绍: The Journal of Physical Chemistry A is devoted to reporting new and original experimental and theoretical basic research of interest to physical chemists, biophysical chemists, and chemical physicists.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:604180095
Book学术官方微信