Theoretical simulation of the molecular structure of a free cyclopentadiene monomer: anticipating the GED experiment

In this study, we performed a quantum chemical (QC) study of the geometry and vibrational spectra of a free cyclopentadiene CPD molecule, with the aim of (i) comparing geometric parameters obtained using various theoretical approaches, (ii) comparing force fields and vibrational frequencies, and (iii) modeling the radial distribution functions for a planned gas-phase electron diffraction (GED) experiment to determine geometric and vibrational parameters of the free CPD molecule with precision, in accordance with modern requirements and using up-to-date experimental techniques and structural analysis of the results of electron diffraction.