COGNAC

English : Japanese

(COarse-Grained molecular dynamics program by NAgoya Cooperation)

COGNAC is a general molecular dynamics simulation program which covers a large class of molecular models, ranging from full atomistic models to bead-spring models. Many potential functions used in coarse-grained models are implemented in COGNAC, such as Lennard-Jones, Gay-Berne and Coulombic potentials, and new potential functions can be added easily. COGNAC can conduct MD simulations under various conditions such as under constant temperature, under deformation (elongation and shear), and under external fields. COGNAC has a special function, called zooming, which generates the equilibrium molecular configuration for given density profile of atoms.

Basic functions

Molecular dynamics/Langevin dynamics/Energy minimization
Potential :
- two, three, and four body bonding potential
- Non-bonding interaction, e.g. LJ, GB, Coulomb
- External potential, e.g. electric field, solid wall
Ensemble : NVE/NVT/NPH/NPT and non-equilibrium dynamics
Chemical reaction
Initial structure generation, e.g. amorphous, helix, crystal
Functions for zooming

Examples of applications

Chain conformation of phase-separated block copolymers
nterfacial properties of polymer blends
Properties of semi-crystalline lamellae
Elastic properties of network polymers
Clay-polymer nanocomposites
Dynamics of confined polymer melts
Phase transition of liquid crystals
Ion diffusion in polyelectrolytes


Block copolymer : Lamellar structure of ABA tri-block copolymer. Initial chain configuration is generated from the information obtained by SUSHI.	Topological gel : Snapshot of a topological gel under elongation. Unique elastic properties of topological gels are reproduced by COGNAC.	Liquid crystal : Snapshot of a liquid crystalline phase obtained for a molecular system consisting of rigid and flexible parts by COGNAC. The rigid part is approximated by an ellipsoid.

COGNAC Slide Show