1. Laboratoire de Modélisation et Simulation en Sciences des Matériaux, Université Djillali Liabès de Sidi Bel-Abbès, Sidi Bel-Abbès 22000, Algeria
2. Faculty of Nature and Life Science, University of Chlef 02000, Algeria
3. Physics Department, University of South Africa, Pretoria 0001, South Africa
4. Department of Physics, University of York, Heslington, York YO10 5DD, UK