Coordination Numbers and Critical Topology of Hydrocarbons with Z″ = 2

Abstract

A statistical analysis of molecular coordination numbers for the crystal structures of 316 bisystem hydrocarbons with Z″ = 2 is carried out. The relationship between coordination numbers, the topological type of networks, and the intermolecular interaction energy calculated by the 6-exp method is studied. It is found that critical networks most often do not correspond to the criteria of minimum networks, i.e. a set of contacts generating the crystal structure is redundant for the structural class. The geometric and energy criteria of the critical network are shown to yield inconsistent results in the structures of bisystem hydrocarbons more often than in monosystem ones.