Binding Energy per nucleon vs A Plot

a1=14.1; a2=13.0; a3=0.595; a4=19.0; a5=33.5; A=2:300; Z=(1/2).*A./(1+A.*(2/3)*(a3/4*a4)); b=mod(Z,2); c= mod(A,2); if b==c if c==0 BE=a1-(a2./A.^(1/3))-(a3.*Z.^2./A.^(4/3))-(a4.*((A-(2.*Z)).^2)./A.^2)+(a5./A.^(7/4)); elseif b==1 BE=a1-(a2./A.^(1/3))-(a3.*Z.^2./A.^(4/3))-(a4.*((A-(2.*Z)).^2)./A.^2)-(a5./A.^(7/4)); end

else BE=a1-(a2./A.^(1/3))-(a3.*Z.^2./A.^(4/3))-(a4.*((A-(2.*Z)).^2)./A.^2); end plot(A,BE)

This is the plot written by me to plot Binding energy Per nucleon vs A ,Don't know why but the plot made by this code is very much different from the real plot ,So cn u plz tell me where I have done mistake ? thnx