Programme

P.48 -- Posters, VCTP-50

Date: Tuesday, 5 August 2025

Time: 08:30 - 10:00

Retrieving Anharmonic Interatomic Potentials from Conventional and Laser-Induced Electron Diffraction

Hien T. Nguyen (1,2,3), Doan-An Trieu (4), Duong D. Hoang-Trong (4), Van-Hoang Le (4), Ngoc-Loan Phan (4)

(1) Department of Theoretical Physics, University of Science, Ho Chi Minh City, Vietnam. (2) Vietnam National University, Ho Chi Minh City, Vietnam. (3) Department of Physics, Tay Nguyen University, Buon Ma Thuot City, Vietnam. (4) Computational Physics Key Laboratory K002, Department of Physics, Ho Chi Minh City University of Education, Ho Chi Minh City, Vietnam.

Retrieving structural information and interatomic potentials from electron diffraction is essential for understanding molecular dynamics at the quantum level. While conventional electron diffraction (CED) has long been used for static imaging, laser-induced electron diffraction (LIED) offers femtosecond-scale temporal resolution, enabling real-time tracking of structural changes. However, the role of nuclear vibrations in shaping diffraction signals remains underexplored, especially in LIED where intense laser fields can amplify vibrational effects. The goal of this study is to assess the influence of nuclear vibrations on diffraction patterns and to evaluate whether anharmonic interatomic potentials can be reconstructed from both CED and LIED signals. We simulate diffraction images for both methods, incorporating thermal nuclear motion in CED and laser-induced vibrations in LIED. In the CED case, we find that diffraction images are most sensitive to interatomic distance, while sensitivity to anharmonic Morse parameters is weaker but still measurable with high precision. In LIED, we develop a method to include laser-driven nuclear dynamics and show that intense laser fields broaden the nuclear wavepacket, enhance population of higher vibrational levels, and significantly increase sensitivity to anharmonic potential shapes. These results demonstrate that LIED is a viable route for reconstructing anharmonic interatomic potentials, with broader applicability beyond the Morse model used in this work.

Presenter: Nguyen Thị Hien