<div dir="ltr">Hi all, I am running CI-NEB calculations in order to locate transition states along a reaction profile involving organometallic species in the solid state. More precisely, this is a hydrogenation reaction of double bonds, i.e. addition of H2 to an alkene. This should be a straightforward task. Anyway, for some cases it seems the SCF encounters problems to converge, or converges to the wrong electronic state. In particular, those replicas are affected which lead to the transition state. I can see that the electronic structure may be a bit tricky, since in a TS notable rearrangement of the electrons takes place. It goes without saying, that having a wrong electronic structure in the TS leads to unreasonably high barriers. I should add that these type of calculations haven't imposed any problems so far using other codes. What causes some additional puzzlement is the fact that for the same TS search slightly different input geometries lead to very different behaviour of the SCF. In one case there is reasonable convergence to a decent electronic structure, in the other case the SCF goes completely havoc. So my question really is, how can I control the SCF convergence for a particular replica? Can this be done in the main input file? your comments are appreciated Tobi </div>