University of Kashan Iranian Journal of Mathematical Chemistry 2228-6489 1 Issue 1 (Special Issue on the Role of PI Index in Nanotechnology) 2010 04 01 Computation of Co-PI Index of TUC4C8(R) Nanotubes 119 123 5142 10.22052/ijmc.2010.5142 EN F. HASSANI Payame Noor University, PNU Central Branch, Iran O. KHORMALI Tarbiat Modares University, Iran A. IRANMANESH Tarbiat Modares University, Iran Journal Article 2014 04 20 In this paper, at first we introduce a new index with the name Co-PI index and obtain some properties related this new index. Then we compute this new index for TUC4C8(R) nanotubes. Vertex-PI index Co-PI index TUC4C8 (R )Nanotube https://ijmc.kashanu.ac.ir/article_5142_619e84597c93a403ee5b4b0eaff4e4c0.pdf