Refractive index of VO2 (Vanadium dioxide)

import lightsmith as ls

# VO2 (Vanadium dioxide): Oguntoye et al. 2023: n,k 0.21–2.5 µm; 20 °C
vo2 = ls.fetch_refractiveindex("main", "VO2", "Oguntoye-20C", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(vo2.range_nm)  # (210, 2500) nm
eps = vo2.eps([633])  # complex permittivity

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_c7fa075ca4c4/lightsmith"
vo2 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(vo2.source)  # citation and provenance travel with the data

# ... load vo2 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=vo2)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=400, stop_nm=1000, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength