Joint Experimental and Theoretical Study on Vibrational Excitation Cross Sections for Electron Collisions with Diacetylene

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• 作者：Roman 膶ur铆k ; Ivana Paidarov谩 ; Michael Allan ; Petr 膶谩rsky
• 刊名：Journal of Physical Chemistry A
• 出版年：2014
• 出版时间：October 16, 2014
• 年：2014
• 卷：118
• 期：41
• 页码：9734-9744
• 全文大小：804K
• ISSN：1520-5215

文摘

We have measured and calculated differential and integral cross sections for elastic and vibrationally inelastic electron scattering by diacetylene molecules at electron energies from 0.5 to 20 eV in the whole range of scattering angles from 0 to 180掳. The calculations were carried out using the discrete momentum representation method (DMR), which is based on the two-channel Lippmann鈥揝chwinger equation in the momentum space. The interaction between the scattered electron and the target molecule is described by the exact static-exchange potential. Correlation鈥損olarization forces are included by a local density functional theory. Energy dependences of integral and differential cross sections are presented for all nine vibrational modes. A detailed comparison of theoretical and experimental electron energy loss spectra is presented for electron energies of 1, 5.5, 10, and 20 eV. The theory assigns symmetry of resonances that could not be determined by empirical analysis alone. The theory reveals, and quantitatively describes, the switching of partial waves accompanying excitation of nontotally symmetrical vibrations. Limitations of the theory in reproducing experimental data for the narrow 蟺* resonance below 2 eV are mentioned.