Hi All: After posting a previous message in the list, I got the information that since my processor is a Intel Pentium D (EM64T), I need to use amd64 as the target during the compilation of GAMESS. However, it seems like g77 for x86_64 machine doesn't work for compile GAMESS, in this case. Could anyone, please, let me know how could I overcome this problem? Should I install another compiler and, if affirmative, where could I find a free compiler for that? Thanks! Best, Hoffmann __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com