Integrated Simulation System for Soft Materials.

Main functions of J-OCTA

Molecular dynamics simulation (COGNAC , VSOP)

• Evaluation-estimation of static and dynamic characteristics of materials from the atomic/molecular level.
• Supports all-atom model (detailed model dealing with all atoms) and coarse-grained model (model dealing with groups of atoms as units).
• Possible to calculate phenomena on a larger scale and over a longer period using coarse-grained model. Possesses a function for estimating coarse-grained potential.
• By writing chemical formulae on the screen, force-field parameters in all-atom model are set and 3D molecular structures can be easily created. Force-field parameters : AMBER , GAFF , DREIDING, some parameters for inorganic materials. Setting parameters from reference papers is possible.
• Estimation of point charge by Quantum Chemical calculations ( Direct interface for Gaussian and PC-GAMESS/Firefly ).
• Interface for Direct Force Field (Team Force Field)
• Construction of block copolymers and random copolymers, as well as polymer tacticity control, etc. can also be performed easily.
• Coupling with other scale. (Zooming, Reverse mapping)
• Converter Functions for LAMMPS and GROMACS
• VSOP is a high-speed parallel MD simulation engine developed by JSOL and JAEA. Large scale simulation is possible using same interface with COGNAC .

Modeling of the Inorganic/Organic Interface		Monomer Modeling

Polymer Modeling		Radial Distribution Function for coarse grained units and Coarse Grained Potential (non-bond).
Full Atomistic and Coarse Grained model

• Parallel Performance of VSOP (Parallel molecular dynamics engine)
  The following figures show parallel performance of VSOP (Bead-Spring Model).
  The left-hand figure is 6.8 million particles and the right-hand figure is 63 million particles.
  From 8 to 1024 parallel, calculation time is shortened approximately linearly, and VSOP keeps high performance.
  By using VSOP, calculation speeds increase dramatically and large-scale calculations are possible.
  ** We used a super computer of Foundation for Computational Science (FOCUS) for velocity measurement.