I've done a lot of experimental work in materials science and solid-state physics, but I'm currently venturing into the computational realm. I'm trying to compute optical constants ($n$ and $k$) for a certain composite material, but the model requires the dielectric function $\epsilon(\lambda$) of the two constituent materials. I've seen many papers that use these functions to generate spectra; where can I find these functions?
The materials I'm concerned with are VO$_2$ nanocrystals dispersed in a host matrix of In$_2$O$_3$ nanocrystals.