On the Convergence of QM/MM Energies
We have studied the convergence of QM/MM calculations with respect to the size of the QM system. We study a proton transfer between a first-sphere cysteine ligand and a second-sphere histidine group in [Ni,Fe] hydrogenase and use a 446-atom model of the protein, treated purely with QM methods as a reference. We have tested 12 different ways to redistribute charges close to the junctions (to avoid
