CH₄ (Methane)

Gases

6 datasets, together covering 0.002–100 µm. Default: Rollefson and Havens 1940: Gas at 0 °C; n 1.68–14.8 µm.

Compare datasets

Tick datasets in the list to add them to the plot (up to 12).

Datasets

Gas

Liquid

Solid

Use it in Lightsmith

Load this data in Python, simulate in one more line

pip install lightsmith

import lightsmith as ls

# CH4 (Methane): Rollefson and Havens 1940: Gas at 0 °C; n 1.68–14.8 µm
ch4 = ls.fetch_refractiveindex("organic", "methane", "Rollefson", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(ch4.range_nm)  # (1680, 14800) nm
eps = ch4.eps([4990])  # complex permittivity

Downloads the original record once (pinned to the imported snapshot) and caches it.

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_0294be54ca49/lightsmith"
ch4 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(ch4.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (methane/rollefson-havens-1940).

# ... load ch4 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=ch4)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=1680, stop_nm=14800, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength

Same spec runs with DDA, FDTD, BEM or T-matrix: ls.compare(sim, ["mie", "dda"]).

Materials guide Open a sphere of it in Studio Quick start Ask the community

Lightsmith is open source (MIT): Mie, T-matrix, BEM, DDA, FDTD, RCWA, TMM, mode solvers and inverse design behind one spec, on CPU or GPU. GitHub.

About CH4 (Methane)

Methane (CH₄) is the simplest alkane and is a colorless, odorless gas under standard conditions. It is the primary constituent of natural gas and is notable for being a potent greenhouse gas. In the environment, methane is produced during the anaerobic decomposition of organic matter, such as in wetlands, ruminant digestion, and landfills. It can also be found in various industrial processes and is used as a fuel for heating and electricity generation. In the realm of optics, methane's refractive properties might be of interest, especially when considering its potential presence in gaseous atmospheres of extraterrestrial bodies.

Other names: CH4, CH₄, Tetrahydridocarbon

API: /v1/materials/mat_fbcfaf1a55b5 · slug methane