2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/224314We study the structure of the twist grain boundary in chiral smectic liquid crystals using the Landau-de Gennes model. By considering spatial variation of the smectic order, we distinguish the Melted-Grain-Boundary-A (MGBA) structure with cholesteric-like domains and the Twist-Grain-Boundary-A (TGBA) structure consisting of screw dislocations. The MGBA structure becomes stable near the transition to the cholesteric phase. On approaching the transition, the cholesteric-like domain grows outside the grain boundary. Also, the dislocation spacings of the TGBA structure agree better with experimental results than previous theories.4 pages, 4 figuresSoft Condensed Mattertext