Topological indices are the molecular descriptors that describe the structures of chemical compounds. They are used in isomer discrimination, structure-property relationship, and structure-activity relations. The topological indices are used to predict certain physico-chemical properties such as boiling point, enthalpy of vaporization, and stability. In this paper, the inverse sum indeg index is studied. This index ( ISI ( G )) is defined as ∑ d u d v d u + d v $\sum \frac {d_{u}d_{v}}{d_{u}+d_{v}}$ . The inverse sum indeg index of some graph operations is computed. These operations are join, sequential join, cartesian product, lexicographic product, and corona operation.

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关于一些图操作的逆和 indeg 索引

拓扑指数是描述化合物结构的分子描述符。它们用于异构体鉴别、结构-性能关系和结构-活性关系。拓扑指数用于预测某些物理化学性质，例如沸点、汽化焓和稳定性。本文研究了逆和 indeg 指数。该指数 (ISI (G)) 定义为 ∑ dudvdu + dv $\sum \frac {d_{u}d_{v}}{d_{u}+d_{v}}$ 。计算一些图操作的逆和 indeg 索引。这些操作是连接、顺序连接、笛卡尔积、字典积和电晕操作。