1. Materials Research Centre
2. Solid State and Structural Chemistry Unit
3. Department of Physics, Goa University, Taleigao Plateau, Goa 403206, India
4. Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur Campus, Bangalore 560064, India
5. Institute of Scientific and Industrial Research, Osaka University, Mihoga-oka 8-1, Ibaraki, Osaka, 567-0047, Japan