Various types of coordination numbers in molecular crystals are discussed. The relationship between parameter R of the Delone system, coordination number (CN), topological type, and the intermolecular interaction energy is studied on the example of crystal structures of centrosymmetric hydrocarbons. The first coordination sphere of a molecule takes 86.2±1.6% of the lattice energy; the interactions providing molecular arrangement take at least 50% of the lattice energy for CN ≥ 6. The nets characterizing the framework of intermolecular interactions in this series of structures tend to the lowest cyclomatic number of the quotient graph.

中文翻译：

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中心对称烃的配位数和临界拓扑

讨论了分子晶体中各种类型的配位数。以中心对称烃的晶体结构为例，研究了Delone系统参数R、配位数(CN)、拓扑类型和分子间相互作用能之间的关系。分子的第一配位球占晶格能的 86.2±1.6%；对于 CN ≥ 6，提供分子排列的相互作用至少占晶格能的 50%。表征这一系列结构中分子间相互作用框架的网络趋向于商图的最低圈数。