I tried using the silicon alpha data to simulate the optical constants of silicon from the paper by D. E. Aspnes and A. A. Studna: Dielectric functions and optical parameters of Si, Ge, GaP, GaAs, GaSb, InP, InAs, and InSb from 1.5 to 6.0 eV (Phys. Rev. B 27, 985-1009, 1983), but I found that the results did not match well.
Are there any methods to improve this? Thank you.