Dear Sayan,

Could you attach the required input to reproduce the convergence issue?

I seem to have even larger issues with the system than you. I'm getting lots of errors and don't understand them yet.

In general what might help with convergence problems is setting the maxIterBroyd parameter to something smaller like maybe 15. Beyond that I discussed a few convergence tricks there: differ error for ZnO slab

What I also observe is that you film setup is kind of asymmetric. That may be another issue in obtaining a nicely converged solution.

You are probably also aware that LDA+U also depends on the starting point which you may more clearly specify by setting a cerrtain density matrix. I could imagine that an unfortunate starting point might also hinder convergence.