1. Department of Physics, Indian Institute of Technology Patna, Bihta 801103, India
2. The Bremen Center for Computational Materials Science (BCCMS), Universität Bremen, Am Fallturm 1, TAB Building, 28359 Bremen, Germany
3. Global innovative Centre for Advanced Nanomaterials (GICAN), University of Newcastle, University Drive, Callaghan, NSW 2308, Australia