Smoothed Dissipative Particle Dynamics

An isothermal implementation of SDPD for water based on Español and Revenga, Phys. Rev. E 67, 026705 (2003)

Installation

• Put the patch file in your top-level LAMMPS directory, where the LICENSE and README files are.

• Apply the patch by typing the following command in your top-level LAMMPS directory:

    patch -p1 < patch.sdpd
  

• Then include USER-SPH package by typing the following commands in src directory:

    make yes-user-sph
  

• The RIGID package is a prerequisite for fix rigid/meso. If you like to be able to integrate rigid bodies motion, include this as well:

    make yes-rigid
  

• Now include the USER-SDPD package

    make yes-user-sdpd
  

• Then build again as usual.

Improving performane with Zest

Most of the time in SDPD simulations are spent producing random gaussian numbers. By default LAMMPS uses the Box-Muller algorithm to produce random gaussian numbers which is inefficient. The Zest library can produce random gaussian numbers much more efficiently. Using Zest, SDPD simulations are sped up y a factor of about 3. Obtain Zest from https://github.com/DiscreteLogarithm/Zest , then copy the header files either into the src directory of the LAMMPS or into your system's include path. Then compile LAMMPS with -DUSE_ZEST flag by adding -DUSE_ZEST to the LMP_INC variable of your preferred Makefile.

LAMMPS uses an old integer random number generator - RANMAR - which has a relatively low period compared to modern standards. When LAMMPS is compiled with Zest the 64-bit version of the Mersenne twister is used which is the de-facto gold standard of uniform random number generators.

Uninstallation

• Use following command in src directory:

    make no-user-sdpd
  

• Then build again