Theoretical Simulation of the Temporal Behavior of Bragg Diffraction Derived from Lattice DeformationSupported by the National Key Research and Development Program of China under Grant Nos. 2016YFA0300303, 2017YFA0504703, and 2017YFA0302904, the National Basic Research Program of China under Grant No. 2015CB921304, the National Natural Science Foundation of China under Grant Nos. 11604372, 11474323, 11774391, 11774403, and 61575085, the Strategic Priority

Abstract

A theoretical study on the structural dynamics of the temporal behavior of Bragg diffraction is presented and compared with experimental results obtained via ultrafast electron crystallography. In order to describe the time-dependent lattices and calculate the Bragg diffraction intensity, we introduce the basic vector offset matrix, which can be used to quantify the shortening, lengthening and rotation of the three lattice vectors (i.e., lattice deformation). Extensive simulations are performed to evaluate the four-dimensional electron crystallography model. The results elucidate the connection between structural deformations and changes in diffraction peaks, and sheds light on the quantitative analysis and comprehensive understanding of the structural dynamics.