Abstract
This paper describes practical ferroelectric liquid crystal (FLC) materials and the relationship between their properties and molecular orientations in FLC devices. Dependent upon the device modes and the molecular orientations, the properties such as spontaneous polarization (Ps), tilt angle (Θ), dielectric biaxiality (Δ ϵ), etc. should be optimized. This paper also describes chiral and achiral compounds for practical FLCDs and properties of some FLC materials recently developed.