Utilizing Hirshfeld surface calculations, non-covalent inter-action (NCI) plots and the calculation of inter-action energies in the analysis of mol-ecular packing.

The analysis of atom-to-atom and/or residue-to-residue contacts remains a favoured mode of analysing the mol-ecular packing in crystals. In this contribution, additional tools are highlighted as methods for analysis in order to complement the 'crystallographer's tool', [Spek (2009). . D, 148-155]. Thus, a brief outline of the procedures and what can be learned by using [Spackman & Jayatilaka (2009). , 19-23] is presented. Attention is then directed towards evaluating the nature, . attractive/weakly attractive/repulsive, of specific contacts employing [Johnson (2010). . , 6498-6506]. This is complemented by a discussion of the calculation of energy frameworks utilizing the latest version of . All the mentioned programs are free of charge and straightforward to use. More importantly, they complement each other to give a more complete picture of how mol-ecules assemble in mol-ecular crystals.