Mr. Dashty,

Could you show the end of the output file?

Prof Dashty,

     I have experienced this same problem.  One possibility is to play with the optimized structure.  The end of the output filed may yield some more insight as Prof. Ivanova has requested.

Prof Dashty,

     Another thing that I forgot to mention is to start with optimization using say HF/3-21g*.  That is very quick and gets you in the ball park.  Depending on the size of the basis that you are using, you may also try at least one intermediate size basis set after the HF/3-21g* optimization.  That's what I do.  If you have already done that, just ignore this note{:^)

Dear prof Lieb

thank you so much for your suggestion, but I want to calculate single point energy without change of geometry. would you please give me the other suggestion?

Dear prof Ivanova

Thanks a lot for your attention. I attached my file

Best regards

Hi Prof Dashty,

      I looked at your output and I see the warning, but I also see what looks like a successful exit from Gaussian with the information your requested at the start of the program:

# mp2/6-31g(d) geom=connectivity counterpoise=2

Counterpoise: corrected energy = -10102.057042822390

Counterpoise: BSSE energy = 0.004605126691

I must be missing the point of your question.  Hopefully Prof Ivanova will add insight into your query