# this file is part of refractiveindex.info database
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REFERENCES: |
    A. S. Barker Jr. and M. Ilegems.
    Infrared lattice vibrations and free-electron dispersion in GaN.
    <a href="https://doi.org/10.1103/PhysRevB.7.743"><i>Phys. Rev. B</i> <b>7</b>, 743-750 (1973)</a>
COMMENTS: |
    α-GaN (wurtzite); Ordinary ray (o); 300 K (27 °C).
CONDITIONS:
    temperature: 300
    direction: o
DATA:
  - type: formula 1
    wavelength_range: 0.35 10
    coefficients: 2.60 1.75 0.256 4.1 17.86