some new results on mostar index of graphs

A general bond additive index can be defined as gba(γ)=ʃeεe α(e), where α(e) is the edge contributions. the mostar index is a new topological index whose edge contributions are α(e)=|nu - nv| in which nu is the number of vertices of γ lying closer to vertex u than to vertex v and nv can be defined similarly. in this paper, we propose some new results on the mostar index based on the vertex-orbits under the action of automorphism group. in addition, we detrmined the structures of graphs with mostar index equal 1. finally, we compute the mostar index of a family of nanocone graphs.