Point defects on (-pi)-wedge disclination in nematics

The structure of a point defect in the director field near (-pi)-wedge disc lination line singularity in a thick sample of a nematic liquid crystal is approximately described. The elastic interaction energy of two point defect s of the opposite sign is evaluated. There is always the attraction between two opposite point defects, as expected. Nevertheless, with the defect sep aration their attraction force decreases. When the attraction force is of t he same order as a viscous force acting against a free molecular rotation, the movement of point defects is very slow. For example, the defect separat ion at which the relative velocity of point defects is about approximate to 0.025 mum/day was estimated as approximate to 160 mum.