Comment on "Corresponding states of periodic structures in nematic liquid crystals"

Palangana, Simões, Evangelista, and Arrotéia [Phys. Rev. E 56, 4282 (1997)] (PSEA) propose a general scaling model for periodic wall patterns in the magnetic twist Fréedericksz transition of nematics, performing an elastic energy analysis. We demonstrate that this model is incorrect because it does not consider consistently the hydrodynamic wavelength selection of the observed structures, but is based on the assumption of inappropriate model functions instead. It is shown that experimental data actually contradict the proposed theory. The approach of PSEA is particularly not suited to determine elastic constant ratios of nematic liquid crystals.