Hello everyone, I'm a graduate student in a biophysics lab. I'm trying to run a QM/MM simulation with a protein that binds 3 Ca2+ ions, and as such I am having a devil of a time getting the SCF to converge. I've tried DIIS, KDIIS, damping, and a few other methods to try to get convergence with not much luck. The couple of times it has converged, it was after more than 100 iterations, which is just too expensive. Does anyone have any suggestions of things I could try? It doesn't matter much, but I'm using Orca for the QM portion. Thanks a bunch.