Extended Data Fig. 5: Refractive index of H2O ice.

Red lines present the reported (n,k) from measurements over a broad spectral range74. Our estimate based on the gas phase cross section is shown by the gray line. The dashed line presents the results when the kUV is fitted with a set of Gaussian curves and the solid black line presents the case of a 10,000 cm−1 blue-shift on kUV. This shift brings nVIS closer to the observed value.