da Costa Romarly F, de Oliveira Eliane M, Bettega Márcio H F, Varella Márcio T do N, Jones Darryl B, Brunger Michael J, Blanco Francisco, Colmenares Rafael, Limão-Vieira Paulo, García Gustavo, Lima Marco A P
Instituto de Física "Gleb Wataghin," Universidade Estadual de Campinas, 13083-859 Campinas, São Paulo, Brazil.
Departamento de Física, Universidade Federal do Paraná, CP 19044, 81531-990 Curitiba, Paraná, Brazil.
J Chem Phys. 2015 Mar 14;142(10):104304. doi: 10.1063/1.4913824.
We report theoretical and experimental total cross sections for electron scattering by phenol (C6H5OH). The experimental data were obtained with an apparatus based in Madrid and the calculated cross sections with two different methodologies, the independent atom method with screening corrected additivity rule (IAM-SCAR), and the Schwinger multichannel method with pseudopotentials (SMCPP). The SMCPP method in the Nopen-channel coupling scheme, at the static-exchange-plus-polarization approximation, is employed to calculate the scattering amplitudes at impact energies ranging from 5.0 eV to 50 eV. We discuss the multichannel coupling effects in the calculated cross sections, in particular how the number of excited states included in the open-channel space impacts upon the convergence of the elastic cross sections at higher collision energies. The IAM-SCAR approach was also used to obtain the elastic differential cross sections (DCSs) and for correcting the experimental total cross sections for the so-called forward angle scattering effect. We found a very good agreement between our SMCPP theoretical differential, integral, and momentum transfer cross sections and experimental data for benzene (a molecule differing from phenol by replacing a hydrogen atom in benzene with a hydroxyl group). Although some discrepancies were found for lower energies, the agreement between the SMCPP data and the DCSs obtained with the IAM-SCAR method improves, as expected, as the impact energy increases. We also have a good agreement among the present SMCPP calculated total cross section (which includes elastic, 32 inelastic electronic excitation processes and ionization contributions, the latter estimated with the binary-encounter-Bethe model), the IAM-SCAR total cross section, and the experimental data when the latter is corrected for the forward angle scattering effect [Fuss et al., Phys. Rev. A 88, 042702 (2013)].
我们报告了苯酚（C6H5OH）电子散射的理论和实验总截面。实验数据是通过马德里的一台仪器获得的，计算截面则采用了两种不同的方法，即带屏蔽修正加和规则的独立原子方法（IAM-SCAR）和带赝势的施温格多通道方法（SMCPP）。采用Nopen通道耦合方案中的SMCPP方法，在静态交换加极化近似下，计算5.0 eV至50 eV碰撞能量范围内的散射振幅。我们讨论了计算截面中的多通道耦合效应，特别是开放通道空间中包含的激发态数量如何影响较高碰撞能量下弹性截面的收敛性。IAM-SCAR方法还用于获得弹性微分截面（DCS），并校正实验总截面中的所谓前向角散射效应。我们发现，我们的SMCPP理论微分、积分和动量转移截面与苯（一种与苯酚不同的分子，苯中的一个氢原子被羟基取代）的实验数据非常吻合。尽管在较低能量下发现了一些差异，但正如预期的那样，随着碰撞能量的增加，SMCPP数据与用IAM-SCAR方法获得的DCS之间的吻合度有所提高。当对实验数据进行前向角散射效应校正时[Fuss等人，《物理评论A》88，042702（2013）]，我们目前的SMCPP计算总截面（包括弹性、32个非弹性电子激发过程和电离贡献，后者用二元碰撞-贝特模型估算）、IAM-SCAR总截面和实验数据之间也有很好的一致性。
