  We present a minimal model for simulating dynamics of assorted lipid
assemblies in a computationally efficient manner. Our model is particle-based
and consists of coarse-grained beads put together on a modular platform to give
generic molecular lipids with tunable properties. The interaction between
coarse-grained beads is governed by soft, short-ranged potentials that account
for the renormalized hydrophobic effect in implicit solvent. The model
faithfully forms micelles, tubular micelles, or bilayers (periodically
infinite, bicelles, or vesicles) depending on the packing ratio of the lipid
molecules. Importantly, for the self-assembled bilayer membranes it is
straightforward to realize gel and fluid phases, the latter of which is most
often of primary interest. We show that the emerging physics over a wide range
of scales and resolutions is (with some restrictions) universal. The model,
when compared to other popular lipid models, demonstrates improvements in the
form of increased numerical stability and boosted dynamics. Possible strategies
for customizing the models (e.g., adding chemical specificity) are briefly
discussed. An implementation is available for the LAMMPS molecular dynamics
simulator [Plimpton. J. Comp. Phys. 117, 1-19. (1995)] including illustrative
input examples from the simulations we present.
