[Ifeffit] problem of normalization of feff calculation and experimental spectrum

Hellow,everyone: When the energy range is too short (for instance 60 70 eV,this moment normal normalization in Athena may not be perfect),how to do the normalization of both the feff calculation and experimental spectrum?I want to let feff calculation fit the experiment , so spectrum normalization had better can be express a parameter to be fited,I'm not sure normal edge jump works,anyone have good idea about it ? Thanks, Sincerely, zhanfei