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In the study of molecular compounds, the most promising tool for analyzing atomic structures is a free electron laser [1]. This is due to the difficulties of analyzing molecules using other methods. There are several ways to study the structure of biomolecules, for example, the Sanger method. Such sequencing methods do not provide accurate results at the atomic level of research, while they are lengthy and time-consuming [2]. NMR spectroscopy also has a number of problems in the study of protein compounds, for example, the overlap of lines in the one-dimensional NMR spectrum, which occurs due to the larger number of atoms compared to a simple organic compound. X-ray radiation also does not allow for ultra-high resolution analysis [3]. The disadvantages of existing methods have prompted scientists to search for new ways to study complex molecular structures, namely the use of ultrashort laser pulses in the analysis [4, 5, 6]. In practice, visualizations of various molecules are already being obtained, mostly simple ones such as N2 and O2. The distances between atoms are determined by fitting experimental diffraction images over spectra using the model of independent atoms [7]. However, as the authors of the article [8] note, in order to apply the method to more complex polyatomic molecules and dynamical systems, it is necessary to complicate the procedure for restoring the molecular structure using fitting.
This article continues the development of the method presented earlier [9] for calculating the model of the scattering spectrum of an ultrashort laser pulse with polyatomic structures. The method is based on the search for symmetries in the structure of the sample under study, i.e. repeating atoms. An example would be the repeating nitrogenous bases of DNA. We will simulate the pulse interaction based on a perfectly one-dimensionally aligned ensemble of ClCF3 molecules. The calculation will be performed in two ways. The first method is as if there were no symmetries and repetitions in the ensemble. In this case, the laser pulse is scattered on each atom. The second method is a symmetry calculation, where scattering modeling is performed only on a repeating part of the overall molecular structure, and then summation occurs. The results obtained will be compared with the experiments of [10], where diffraction patterns were obtained by other methods.
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