Hello Q-Chem Community!
Recently I was doing QM/MM and Ab Initio molecular dynamics (AIMD) calculations for solute with explicit solvent molecules. My goal was to somewhat optimize geometries of solvent molecules (MM level) with fixed solute geometry (QM level). When I was doing AIMD calculations I started wondering: during AIMD with QM/MM QM calculations are performed on every molecular dynamics step. I only need to optimize solvent geometries, so fixed QM solute function as an effective potential for solvent molecules. So maybe I would need to perform QM only once and later reuse potential from solute during molecular dynamics (effectively doing only MM and copy/pasting QM results).
I want to ask if there is a possibility of such reusing within Q-Chem? Or maybe there is somewhere a loophole in this idea?
Sincerely,
Tiopirfur
This functionality doesn’t exist because the MM solvent charges should polarize the QM wave function, thus you need to recompute the QM every time the MM molecules move.