Computing Padmakar-Ivan Index of a TC4C8(R) Nanotorus

The Padmakar-Ivan (PI) index of a graph G is defined as PI (G) = Sigma[n(eu)(e | G) + n(ev)(e | G)], where n(eu)(e | G) is the number of edges of G lying closer to u than to v, n(ev)(e | G) is the number of edges of G lying closer to v than to u and summation goes over all edges of G. In this paper, the PI index of a TC4C8(R) nanotorus is computed.