Clustering of nonvalently bonded NO₂…O₂N fragments at C(sp³) atoms

Based on the "invariom" approach and the "Atoms in Molecules" theory, a simplified method is proposed to reveal and analyze bonding interatomic interactions using large arrays of structural data. The technique was tested taking nonvalent interactions between nitro groups bonded to C(sp³) atoms as examples. Geometric clustering of structural fragments was performed and the interaction strength and covalent contribution distributions were analyzed. Relationships between the fragment clustering results and nonvalent bonding pattern features are discussed.