Syntax:
pair_style dpd T cutoff seed
Examples:
pair_style dpd 1.0 2.5 34387 pair_coeff * * 3.0 1.0 pair_coeff 1 1 3.0 1.0 1.0
Description:
Style dpd computes a force field for dissipative particle dynamics (DPD) following the exposition in (Groot). The force on atom I due to atom J is given as a sum of 3 terms
where FC is a conservative force, FD is a dissipative force, and FR is a random force. Rij is a unit vector in the direction Ri - Rj, Vij is the vector difference in velocities of the two atoms = Vi - Vj, alpha is a Gaussian random number with zero mean and unit variance, dt is the timestep size, and w(r) is a weighting factor that varies between 0 and 1. Rc is the cutoff. Sigma is set equal to sqrt(2 T gamma), where T is a parameter in the pair_style command.
The following coefficients must be defined for each pair of atoms types via the pair_coeff command as in the examples above, or in the data file or restart files read by the read_data or read_restart commands:
The last coefficient is optional. If not specified, the global DPD cutoff is used. Note that sigma is set equal to sqrt(2 T gamma), where T is the temperature set by the pair_style command so it does not need to be specified.
Restrictions: none
This style is part of the "dpd" package. It is only enabled if LAMMPS was built with those package. See the Making LAMMPS section for more info.
Related commands:
Default: none