where nint(x) is the nearest-integer function and u ij = u j -u i is a difference vector defined using scaled coordinates, i.e., u i = h -1 R i . The difference vector with the MIC applied as defined in eq (7) thus replaces the vector in eq 5, and, consequently, every polarizable site will interact with the closest periodic image of all other sites through the modified electric fields in eq (4).