Hi all,
I’m trying to do a partially frozen scan where I would like to keep angles and dihedrals frozen but allow bond angles and dihedrals to relax. I tried using a $opt section to constrain the angles/dihedrals, but to no success. I would like to do this since there is an interconversion between two PESs with the same symmetry and I’d like to probe the two surfaces individually. I could write a python script to automatically write several nested calculations within one file, but I’d rather not if there’s an easier way to do this in Q-Chem.
Sure have — the issue is it appears using pes_scan I can only do either a completely relaxed scan or a completely rigid scan — not a partially relaxed scan in which say bends or torsions are frozen but stretches are relaxed.