[1] Tribhuvan Univ, Cent Dept Chem, Kathmandu, Nepal
[2] NPI, Kathmandu, Nepal
[3] Univ Padua, Dipartimento Sci Chim, I-35131 Padua, Italy
[4] Univ Halle Wittenberg, Ctr Engn Sci, D-06120 Halle, Germany
[5] Univ Halle Wittenberg, Inst Phys, D-06099 Halle, Germany
[6] Univ Rouen, Lab LECAP, Inst Mat Rouen, F-76801 St Etienne, France