The Reconstruction of Polarization and Correlation Effects in the Reduced Density Matrix of Urea Crystal

This study investigates the capability of capturing subtle effects, such as intermolecular polarization and intramolecular electron correlation, through a one-electron reduced density matrix reconstruction. Taking urea as a model system, artificial data sets of X-ray diffraction structure factors and directional Compton profiles were generated from known 1-RDMs. The analysis demonstrates that, while the reconstruction method can successfully recover polarization and correlation effects in both position and momentum spaces, capturing their manifestations within the complete 1-RDM remains challenging. Additionally, it is confirmed that Compton data are an essential ingredient in the reconstruction of 1-RDM, thereby substantiating the role of momentum-space information as a powerful complement to X-ray diffraction data. The findings underscore the potential and limitations of reconstructing the detailed quantum properties of molecular crystals from experimental data, paving the way for improved reconstruction techniques.