University of KashanIranian Journal of Mathematical Chemistry2228-648911420201201Some Indices in the Random Spiro Chains25527011129010.22052/ijmc.2020.231652.1502ENHechao LiuSchool of Mathematics and Statistics, Hunan Normal UniversityMingyao ZengSchool of Mathematics and Statistics, Hunan Normal UniversityHanyuan DengSchool of Mathematics and Statistics, Hunan Normal University0000-0003-1680-2473Zikai TangSchool of Mathematics and Statistics, Hunan Normal University0000-0002-2577-7890Journal Article20200517The Gutman index, Schultz index, multiplicative degree-Kirchhoff index, additive degree-Kirchhoff index are four well-studied topological indices, which are useful tools in QSPR and QSAR investigations. Spiro compounds are an important class of cycloalkanes in organic chemistry. In this paper, we determine the expected values of these indices in the random spiro chains, and the extremal values among all spiro chains with n hexagons.https://ijmc.kashanu.ac.ir/article_111290_ddb466c03fbb7c99e7b639afa7c5f505.pdf