This package contains a LAMMPS implementation of a background
Lattice-Boltzmann fluid, which can be used to model MD particles
influenced by hydrodynamic forces.  Details are described in these two
papers:

Mackay, F. E., Ollila, S.T.T., and Denniston, C., Hydrodynamic Forces
Implemented into LAMMPS through a lattice-Boltzmann fluid, Computer
Physics Communications 184 (2013) 2021-2031.

Mackay, F. E., and Denniston, C., Coupling MD particles to a
lattice-Boltzmann fluid through the use of conservative forces,
J. Comput. Phys. 237 (2013) 289-298.

See the doc page for the fix lb/fluid command to get started, and see
brief descriptions of other fixes below, each of which have their own
doc page.

There are example scripts for using this package in
examples/USER/lb.

IMPORTANT NOTE: This package can only be used if LAMMPS is compiled
with MPI (i.e. the serial makefile should not be used to compile the
code).  Also, several of the test examples provided make use of the
rigid fix.  Therefore, this should be included in the LAMMPS build by
typing "make yes-rigid" prior to the usual compilation (see the
"Including/excluding packages" section of the LAMMPS manual).

The creators of this package are as follows:

Frances Mackay
University of Western Ontario
fmackay@uwo.ca

Dr. Colin Denniston
University of Western Ontario
cdennist@uwo.ca

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Fixes provided by this package:

fix_lb_fluid.cpp:  fix used to create the lattice-Boltzmann fluid on a 
		   grid covering the LAMMPS simulation domain.

fix_momentum_lb.cpp:  fix used to subtract off the total (atom plus fluid) 
		      linear momentum from the system.

fix_pc.cpp:  integration algorithm for individual atoms.

fix_rigid_pc_sphere.cpp:  integration algorithm for rigid spherical 
			  collections of atoms.

fix_viscous_lb.cpp:  fix to add the fluid force to the atoms when using a
		     built-in LAMMPS integrator.
