Project combines two experimental procedures to gain information about the bonding environment focusing on polycyclic aromatic compounds. The indirect spin-spin coupling constants ⁿJ(¹³C-¹³C) will be measured by means of advanced NMR spectroscopy. The nJ values reflect the electron density distribution between two particular atoms. The NMR data will be correlated to the structural parameters (bonding distances and angles) provided by X-ray single crystal analysis. The found correlations will enable mutual prediction of these data. Both data types will also serve for the calibration of DFT calculations. Furthermore, suitable single crystals will be selected for experimental determination of charge density distribution. The results (critical points, partial charges etc.) will be also correlated to the original NMR data and also compared to DFT results. Final analysis of the liquid state (NMR) and vacuum (DFT) data when compared to XRD data will reveal the contribution of the intermolecular interactions in the packing to the final electron density distribution in a given molecule.