Dear Julian,

I want to describe the interatomic potential of ionic crystals using Coulomb potential and Buckingham potential. I wonder if I can specify the cutoff radius manually for the Ewald calculation, that is, if r is less than the cutoff radius the coulomb interaction will be calculated in lattice sums (real space). I found the default cutoff radius in GULP is 12 angstrom.

Thanks very much.

Best regards,

Junwei