Dividing Planes of Hexagonal H_II Mesophase

Presented is a brief review of the cylindrical dividing surfaces (planes) of the hexagonal inverse H II phase-Luzzati, pivotal, and neutral. They are presented as interrelated surfaces through the general expression of elastic energy per molecule valid for the corresponding surface. For each of the planes, the routine for deriving the plane parameters- radius, area, and volume per molecule, as well as their role in terms of mechanical description the of H II phase-is described in detail. Special attention is paid to the numerical routines for parameter calculations from experimental data, using least-squares routines and the related methods of merit function optimization (minimization). In addition, cases of error estimation are presented along with discussions about the accuracy of used numerical routines.