Refractive index of CsPb(Br,Cl)3 (Cesium lead tribromide - Cesium lead trichloride)

import lightsmith as ls

# CsPb(Br,Cl)3 (Cesium lead tribromide - Cesium lead trichloride): Ermolaev et al. 2023: Br-1.3, Cl-1.7; n,k(o) 0.455–0.500 µm
cspb = ls.fetch_refractiveindex("other", "CsPb_BrCl_3", "Ermolaev-Br1.3Cl1.7-o", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(cspb.range_nm)  # (455, 500) nm
eps = cspb.eps([477])  # complex permittivity

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_56dc8743bb09/lightsmith"
cspb = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(cspb.source)  # citation and provenance travel with the data

# ... load cspb as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=cspb)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=455, stop_nm=500, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength