{
  "hydrogen": {
    "sigma": [
      -1.4165,
      0.746383,
      0.675625
    ],
    "n": [
      0.63882,
      0.659804,
      0.619149
    ]
  },
  "neon": {
    "sigma": [
      0.012254,
      0.02728,
      -0.025715
    ],
    "n": [
      1.4136,
      1.4517,
      1.6567
    ]
  },
  "para-hydrogen": {
    "sigma": [
      0.005314
    ],
    "n": [
      1.06
    ]
  },
  "deuterium": {
    "sigma": [
      0.009376
    ],
    "n": [
      1.258
    ]
  },
  "helium": {
    "sigma": [
      0.0004656,
      0.001889,
      -0.002006
    ],
    "n": [
      1.04,
      2.468,
      2.661
    ]
  }
}