We need to know the electronegatives of the elements in the compound which are Al and Mn as the %ic is an electronegative function.
Electronegative of Al is 1.5
Electronegative of Mn is 1.6
%ic = [1 - exp(-0.25)(1.6 - 1.5)^2] x 100
%ic = [1 - exp(-0.25)(0.01)] x 100
%ic = 0.25%
