Refractive index of PbTe (Lead telluride)

import lightsmith as ls

# PbTe (Lead telluride): Weiting and Yixun 1990: n 5.19–12.5 µm; 80 K
pbte = ls.fetch_refractiveindex("main", "PbTe", "Weiting-80K", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(pbte.range_nm)  # (5189, 12510) nm
eps = pbte.eps([8060])  # complex permittivity

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_ef0f52ec9d4c/lightsmith"
pbte = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(pbte.source)  # citation and provenance travel with the data

# ... load pbte as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=pbte)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=5189, stop_nm=12510, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength