1. Department of Chemistry and Centre for Theoretical Studies; Indian Institute of Technology; Kharagpur 721302 India
2. Department of Chemistry; Indian Institute of Science Education and Research; Pune Maharashtra 411008 India
3. Department of Chemistry; Udai Pratap Autonomous College; Varanasi Uttar Pradesh 221002 India
4. Departamento De Física Aplicada; Centro De Investigación Y De Estudios Avanzados Unidad Mérida; Km 6 Antigua Carretera a Progreso. Apdo. Postal 73, Cordemex Mérida Yuc 97310 México