“…This expression readily enables the order parameters, hP L i, to be determined from the integrated intensity of the wide-angle X-ray peaks, the method for which is described fully in the literature [23]. As a result of the increasing ease of carrying out X-ray scattering studies of liquid crystal samples, this method has been used widely in the field of liquid crystal studies to interpret experimental data [ 14,15,17,[24][25][26][27][28][29][30][31][32][33][34][35], as well as forming the basis for a number of computational and theoretical studies [36][37][38][39]. Outside the field of liquid crystals, it was noted over a decade ago by Burger and Ruland that there had been an error in the derivation of Equation (4) [40], and that the correct formula had in fact been derived much earlier by Kratky [41].…”