Refractive index of C (Carbon, diamond, graphite, graphene, carbon nanotubes)

import lightsmith as ls

# C (Carbon, diamond, graphite, graphene, carbon nanotubes): Dore et al. 1998: Polycrystalline CVD diamond; n,k 2.5–500 µm
c = ls.fetch_refractiveindex("main", "C", "Dore", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(c.range_nm)  # (2500, 500000) nm
eps = c.eps([35400])  # complex permittivity

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_6e6fe74d358f/lightsmith"
c = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(c.source)  # citation and provenance travel with the data

# ... load c as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=c)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=2500, stop_nm=500000, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength