During focusing calculations, you may encounter the message "WARNING! Unusually large potential values detected on the focusing boundary!" for some highly charged systems based on location of the focusing boundary.

First, you should determine if you received any other warning or error messages as part of this calculation, particularly those referring to exceeded number of iterations or error tolerance (etol). If such messages are received, please contact the developers for support.

Next, you should check if the calculation converged to a reasonable answer. In particular, you should check sensitivity to the grid spacing by making small changes to the grid lengths (via the fglen parameter) and see if the changes in energies are correspondingly small. If so, then this warning can be safely ignored. If not, please contact the developers for support.