Yes, this is a well-known problem that we have tried to pin down (for years now), but we cannot seem to really pin-point it... :(
I would suggest you decrease initial linear mixing to something like 0.0001 and then once pulay mixing enters it should be more stable.
If you can re-create a system with a fast SCF (i.e. very few atoms) it might be easier for us to dig this out? What is the smallest system you see this behaviour for?
Yes, this is a well-known problem that we have tried to pin down (for years now), but we cannot seem to really pin-point it... :(
I would suggest you decrease initial linear mixing to something like 0.0001 and then once pulay mixing enters it should be more stable.
If you can re-create a system with a fast SCF (i.e. very few atoms) it might be easier for us to dig this out? What is the smallest system you see this behaviour for?