Please suggest tools for refining protein models! The tool I use can't handle the size of the protein I'm working on (it has 3128 amino acid residues).
It helps if you actually tell us what you used, so we don't suggest the same tool you already tried. The more you tell us, the more likely it is that you will get a good suggestion. This is to say that two sentence descriptions are usually not enough.
Amber should work with any protein size assuming that you have a relatively modern computer with enough memory - telling us that detail would also make it easier to give advice.
I'll be more specific in the future. I used 3Drefine. Thank you very much for your help!