Dear all,

I use Forcite to optimze an inorganic structure using Dreiding force field. The charges were calculated using QEq. I found the charges in the final structure were the same as those in the initial structure. Should I re-calculate the charges with the new structure to obtain an updated charge distributuion and go on optimizing the new structure with the new charge distribution until it is "converged"? Or is there a way to make forcite update the charge distribution at every optimization step?

Another question is about the constraints during the optimization. I found in Forcite the energy calculation results are different between calculations with and without constraints. I assume some energy terms are omitted for fixed atoms in Forcite and a new energy calculation is needed without any constraint to get the correct energy value. I don't know if DMOL3 do the same thing. To get the correct energy value, should I release all the constraints and run a single energy calculation in DMOL3 again?

Best wishes,

Yi