Disclination

In crystallography, a disclination is a line defect in which there is compensation of an angular gap. They were first discussed by Vito Volterra in 1907, who provided an analysis of the elastic strains of a wedge disclination. By analogy to dislocations in crystals, the term, disinclination, was first used by Charles Frank and since then has been modified to its current usage, disclination. As pointed out by John D. Eshelby, there is an intricate connection between disclinations and dislocations, with dislocation motion moving the position of a disclination.

Disclinations occur in many different materials, including liquid crystals, nanoparticles with decahedral or icosahedral symmetries, and in elastically distorted materials.