Twentanglements is a simulation package for mesoscopic polymer dynamics simulations. The
package contains the Twentanglement uncrossability algorithm, which can be used in several
types of mesoscale simulation methods. The program uses background friction (Langevin
dynamics) or a pairwise friction.
Coarse graining from a molecular dynamics simulation to a mesoscale results in soft repulsive
potentials between the blobs. This will cause unphysical bondcrossings influencing the
dynamics of the system. The Twentanglement uncrossability constraint prevents these bond
crossings. Simulations of a polyethylene melt show that the rheology is described correctly
using this bottom-up method. The blob-blob interactions are deducted from MD simulations, as
well as the friction parameters. No fitting parameters have been introduced!
The complete package includes the Krak mesoscale simulation program. Krak is built around
the Twentanglement subroutine and is capable of simulating various polymeric systems, e.g.
polymer melts, diluted polymers, amphiphilic systems, diblock copolymers, star like polymers, etcetera.
It analyses thermodynamic data, trajectories, average end-to-end vectors, radii of gyration,
order tensors, mean square displacements, autocorrelations (stress, velocity, Rouse modes).
However, the Twentanglement algorithm can also be used as a plugin in your favourite simulation program.
The manual describes the way to implement it.