1. Department of Chemistry, National Institute of Technology Kurukshetra, Kurukshetra-136119, India
2. School of Physics, Indian Institute of Science Education and Research, Thiruvananthapuram-695551, India
3. Helmholtz–Zentrum Berlin für Materialien und Energie, D-14109 Berlin, Germany
4. Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
5. Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai – 400 094, India