Ponnusamy, S., S. Palanisamy, A. D. Stephen, and K. Selvaraju. “A QTAIM Approach on Poly Tetrahydrothiophene Molecular Wire”. Boson Journal of Modern Physics, Vol. 4, no. 2, July 2018, pp. 361-83, http://scitecresearch.com/journals/index.php/bjmp/article/view/1567.