Hi Arnim,

Thank you for your reply. Yes i optimized the structure.

In fact yesterday, I did the calculation again with serial optimization and aoforce. I got 0.17 Ha for small basis set.

I don't know if this is a bug or there is problem with our computers or I did wrong. I used 2 procedures:

- Old one: geometry optimization with jobex parallel. After that compute aoforce (serial) in the same directory. I have 0.21 Ha.

- New one: geometry optimization with jobex serial and then compute aoforce (serial) in same directory. I have 0.17 Ha.

Also, total energy compute with 2 procedures are the same, except ZPE and frequencies.

Best regards,

Quan