Abstract
A numerical method for the analysis of the static and dynamic behaviour of the director field, n, of a nematic liquid crystal is presented, where the equivalence of n and – n is taken into account. The occurrence of defects characteristic of nematics is studied for a hybrid cell, and for a material with a negative anisotropic susceptibility subject to an external field. Typical director configurations with defects are displayed graphically for some two dimensional arrangements and, in addition, the resulting pictures corresponding to an observation between crossed polarizer and analyser have been computed.