Intervalence band absorption spectra of InP and related materials over a range of temperatures are calculated using different k⋅p methods for band structure. It is shown that band structure models which neglect valence band intermixing effects, such as the Kane model, fail to provide any quantitative agreement with experiment. However, the Luttinger–Kohn model [Phys. Rev. 97, 869 (1955)] if properly fitted, does yield quantitatively accurate results for InP, GaAs, and InGaAs, in wide spectral and temperature ranges of interest for practical optoelectronic devices without adjusting the effective masses and split-off energy.