Always, always, always put iop(5/13=1) in your route section for D.01. It prevents a specific rounding error that causes the linker to throw a Segmentation fault when reading checkpoint files.
Have you found a new "Off..." bug in G09W D.01? Let me know in the comments—chances are, I’ve already lost sleep over it. Posts tagged Gaussian 09W 9.5 Revision D.01 Off...
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. Always, always, always put iop(5/13=1) in your route
Let’s be honest—G09W D.01 is quirky. It is the grumpy sysadmin of quantum chemistry software. It works flawlessly until it suddenly doesn’t, usually at 2:00 AM before a paper deadline. Let me know in the comments—chances are, I’ve
D.01 is stubborn, slow, and occasionally infuriating. But it is consistent .