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-- Examples of i-PI working with LAMMPS --
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-- Example with Tersoff graphene potential --
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Uses the Tersoff parameters of Lindsay and Broido PRB 81, 205441 (2010)
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to run a short simulation of graphene with the LAMMPS MD code.
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-- Example with the q-TIP4P-F water potential --
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* This gives an example of water with the q-TIP4P-F potential
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of Scott Habershon, Thomas E. Markland and David E. Manolopoulos,
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J. Chem. Phys., 131, 024501, (2009).
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* State point: (N, V, T) = (216 water molecules, 43737 a_0**3, 298 K)
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* This demonstrates the convergence of the kinetic and potential energy
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using the ring polymer contraction (RPC) method of Thomas E. Markland and
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David E. Manolopoulos, J. Chem. Phys. 129, 024105, (2008), and
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the PIGLET method of Michele Ceriotti and
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David Manolopoulos, Phys. Rev. Lett., 109, 100604, (2012).
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** Run the examples automatically:
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* First, it is necessary to patch and compile LAMMPS, and create a make.in
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file containing the path to the executable and i-pi, e.g.
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LAMMPS:=~/bin/lmp_serial
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* The runs can be done automatically using the Makefile provided. The make
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targets are self-explanatory. To run the RPC example, for instance, just type:
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* To clean up output files:
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** Run the examples manually:
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* Go back to the example directory and run
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$ python path/i-pi input.xml
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the wrapper will start and sit waiting on the UDS /tmp/ipi.
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* Open a separate terminal and run the LAMMPS driver code using:
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$ path/lammps/src/lmp_serial < in.water
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For the RPC run, instead use:
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$ path/lammps/src/lmp_serial < in.water_longrange
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$ path/lammps/src/lmp_serial < in.water_shortrange
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You can run multiple instances of the code; it is so fast that parallel
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scaling won't be appreciable.
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* If your system does not support Unix domain sockets, just set in input.xml
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<socket mode="unix"> <port> port_no </port>
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To make the client socket connect, the in.water file should
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be changed so that it has the line:
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fix 1 all driver hostname port_no
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where hostname is the address the socket is binding to; either graphene, piglet_2,
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piglet_4, piglet_8, rpc_long, rpc_short or no_rpc depending on the run.