Refractive index of Phosphate Buffered Saline (PBS)

import lightsmith as ls

# Phosphate Buffered Saline (PBS): Barroso et al. 2019: DPBS with EDTA and BSA; n 0.5–1.1 µm
pbs = ls.fetch_refractiveindex("other", "PBS", "Barroso-EDTA-BSA", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(pbs.range_nm)  # (500, 1100) nm
eps = pbs.eps([633])  # complex permittivity

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_feaa75d5dee1/lightsmith"
pbs = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(pbs.source)  # citation and provenance travel with the data

# ... load pbs as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=pbs)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=500, stop_nm=1000, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength