Hi Deepak, One of the largest depositories of computational chemistry source code remains QCPE at Indiana University. http://qcpe.chem.indiana.edu/ Good luck, Don Donald B. Boyd, Ph.D. Editor, Reviews in Computational Chemistry http://chem.iupui.edu/rcc/rcc.html Editor, Journal of Molecular Graphics and Modelling (publication of the ACS COMP division and MGMS) http://chem.iupui.edu/~boyd/jmgm.html E-mail boyd |-at-| chem.iupui.edu