How to Calculate Fukui function at different charges using DMOL3?

Dear Users will you let me know how to calculate Fukui function (FF) values at different charges (e.g., +0.05, +0.025, +0.2, -0.05, -0.025, -0.2). Right now the default charge values to calculate FF values are -0.1 and +0.1 for f(+) and f(-), respectively.