Crystal structure Hydrogen bonds Ions Non-covalent interaction Single crystals crystal structure Ab initio calculations Adhesion Atoms in Molecules Bond length Bond lengths and angles Calculations Carboxamide Carboxamides Cluster calculations Co-operative effects Cohesion energy Comparative analysis Computational chemistry Crystal atomic structure Cyclohexane DSC Differential scanning calorimetry Electron-density topology Enthalpy Halogen bonding Hexane Hydrogen bond interaction IR and Raman spectroscopy IR spectroscopy