Dear all I am studying optical properties of Noble metals, but plasma frequency is overestimated in all the cases SIESTA(~eV) Exp(~eV) Cu 15 8 Au 22 6 Ag 18 4 Pt 25 7 My different parameters are K Monkhrost pack 15x15x15 Optical mesh 45x45x45 Optical broaden 0.2 eV K points 1688 No of bands 15 Relaxation time varied from 0.1 to 0.001 Ha At 0.001 Ha of relaxation time, there is better matching of imaginary part of dielectric function. I dont know that where is the problem regarding overestimation of relaxation time. Please help. Many thanks in advance for your help, With regards Arun Kumar Research Scholar Deptt of Physics Himachal Pradesh University Shimla-5 Himachal Pradesh India
