README
8ccb8bfd6668lammm-master-deprecated

README
View Options

			This directory has a C++ code multiple.cpp which illustrates how a
			driver code can create multiple instantiations of LAMMPS to run
			independent simulations simultaneously, on a set of processors
			allocated by MPI.

			Once you have built LAMMPS as a library (see examples/COUPLE/README),
			you can then build the driver codes with compile lines like these,
			which include paths to the LAMMPS library interface, MPI (an installed
			MPICH in this case), and FFTW (assuming you built LAMMPS as a library
			with its PPPM solver).

			g++ -I/home/sjplimp/lammps/src -c multiple.cpp
			g++ -L/home/sjplimp/lammps/src multiple.o \
			-llammps -lfftw -lmpich -lmpl -lpthread -o multiple

			If you then run this command:

			% mpirun -np 8 multiple 4 in.chain 1.0 0.5

			you will create 4 instances of LAMMPS, each running on 2 of the
			allocated 8 processors. The final two arguments are the base
			temperature and a delta temperature added by each instance. The
			provided input script in.chain uses those temperatures, set as a
			variable "t" when each instance of LAMMPS is created.

			After a few seconds you should get this output to the screen:

			Instance 1, final temp = 1.00469
			Instance 2, final temp = 1.50395
			Instance 3, final temp = 1.99873
			Instance 4, final temp = 2.50862

			indicating the runs equilibrated to 4 temperatures separated by 0.5
			(in LJ units). There should also be 4 screen files (screen.N) and 4
			log files (log.lammps.N) from the individual LAMMPS runs.