The Edge Szeged Index of Polyomino Chains of 4k-Cycles

The edge Szeged index is a new molecular structure descriptor equal to the sum of products n _{eu}(e | G)n_{ev} (e | G) over all edges e=uv of the molecular graph G, where n_{eu} (e |G) is the number of edges which its distance to vertex u is smaller than the distance to vertex v, and n_{ev} (e | G) is defined analogously. In this paper we compute the edge Szeged index of polyomino chains of 4k-cycles and establish bounds for it.