A Cinema 4D tag plugin for import refractiveindex.com (k and n) to curve in Cinema 4D
Then you can apply them and change them anywhere and as you want !
You can download it from here or directly from my website http://graphos.xyz/files/Plugin/graph_refractive_index/graph_refractive_index.zip
Copy / Paste in your Cinema 4D plugin
Windows and Mac R16 +