Refractive index of BaTiO₃ (Barium titanate)

import lightsmith as ls

# BaTiO3 (Barium titanate): Timpu et al. 2019: n 0.4–0.8 µm
batio3 = ls.fetch_refractiveindex("main", "BaTiO3", "Timpu", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(batio3.range_nm)  # (350, 800) nm
eps = batio3.eps([633])  # complex permittivity

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_bd723a1b866e/lightsmith"
batio3 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(batio3.source)  # citation and provenance travel with the data

# ... load batio3 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=batio3)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=400, stop_nm=800, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength