Here are the three most common "Off..." scenarios I’ve debugged with this specific revision, and how to fix them. The symptom: Your molecule starts optimizing fine, then suddenly the bonds stretch to 5 Angstroms, and the energy goes positive. The log file says Optimization stopped without a clear reason.
Ghosts in the Machine: Troubleshooting Gaussian 09W Rev. D.01 (and Why You Might Still Need It) Posts tagged Gaussian 09W 9.5 Revision D.01 Off...
Gaussian 09W 9.5 Revision D.01
If you are still running , you are likely in one of two camps: a computational chemist clinging to a validated workflow, or a graduate student forced to use the license dongle from 2014 that refuses to die. Here are the three most common "Off