Programme

P.35 -- Poster, VCTP-44

Date: Tuesday, 30 July 2019

Time: 08:30 - 10:00

Vibration effect on the elastic differential cross section in the gas-phase electron diffraction within the multiple scattering model

Hien T. Nguyen (1,2), Ngoc-Loan T. Phan (3)

(1) Tay Nguyen University, Buon Ma Thuot City, Vietnam, (2) VNUHCM-University of Science, Ho Chi Minh City, Vietnam (3) Ho Chi Minh City University of Education, Ho Chi Minh City, Vietnam Email: nthien@ttn.edu.vn

The gas-phase electron diffraction has been an effective method for determining the structure of molecular [1]. For retrieval of the molecular structure, several simple models such as the independent-atoms model (IAM) [2] and the multiple scattering model (MS) [3] were applied for calculating the electron-molecule differential cross section (DCS). While the IAM is validated sufficiently for an electron-molecule collision at high energy only, the MS also works well at the immediate and low energies [2, 3]. Beside the DCS, the molecular scattering intensity and the radial distribution function, which directly contain the molecular structure, are significant for the molecular structure retrieval [1]. Mainly, due to the contribution of each atomic pair to the diffraction intensity caused by the electron scattering on the molecule, the interatomic separations are clearly shown by the peaks of the radial distribution curve [1]. Within the IAM, molecular vibration distorts the DCS, molecular scattering intensity, and radial distribution function; as a consequence, its inclusion corrects the molecular retrieval structure [4, 5]. However, the MS developed for intermediate and low energies of the electron-molecule collision has not considered the vibration effect [3]. In this report, we show how to include the molecular vibration to the MS. Applying these calculations to some gas-phase molecules, we compare the applicability of the two models, IAM and MS. Furthermore, we analyze the energy region of electron scattering where the MS is highly accurate and, consequently, the included molecular vibration effect can be noticeable. Finally, we investigate the influence of the vibration effect on the molecular structure retrieval. REFERENCES [1] J. C. Williamsont and A. H. Zewail, J. Phys. Chem. 98, 2766 (1994). [2] J. Xu, Z. Chen, A. Le, and C. D. Lin, Phys. Rev. A 82, 033403 (2010). [3] D. D. T. Vu, N. L. T. Phan, V. H. Hoang, and V. H. Le, J. Phys. B 50, 245101 (2017). [4] L. S. Bartell, J. Chem. Phys. 1219, 1219 (2006). [5] M. Tanimoto, K. Kuchitsu, and Y. Morino, Bull. Chemiscal Soceity Japan 43, 2776 (1970).

Presenter: Nguyen Thi Hien