2. The total energy, E* of a spin-up band of conduction electrons in a ferromagnetic material is given by E* = E.(1 + () /3 -=VN2(1 + ()2 -=NUB(1 + () N Write a complete Fortran program that calls a user defined function to calculate the value of E*. Use appropriate technique to obtain the parameters on the right- hand side of the equation and pass them to the function. All input and output must be performed in the main program. Use comment lines in the source code to describe your strategy to test the program. Test your program rigorously using suitable data. (10/100 marks)