Smectic

The smectic phases, which are found at lower temperatures than the nematic, form well-defined layers that can slide over one another in a manner similar to that of soap.[…]There are many different smectic phases, all characterized by different types and degrees of positional and orientational order.^([Wikipedia])

Before studying the fluctuations and defects of the bilayers in the smectic phase, one should first characterize the equilibrium structure of the simulated lamellar phase.