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"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Section_commands.html#comm)
:line
fix ipi command :h3
[Syntax:]
fix ID group-ID ipi address port [unix] :pre
ID, group-ID are documented in "fix"_fix.html command :ulb,l
ipi = style name of this fix command :l
address = internet address (FQDN or IP), or UNIX socket name :l
port = port number (ignored for UNIX sockets) :l
keyword = {unix} If present uses a unix socket
:ule
[Examples:]
fix 1 all ipi my.server.com 12345
fix 1 all ipi mysocket 666 unix
[Description:]
Runs LAMMPS as a client for the i-PI Python wrapper for
path integral molecular dynamics "(IPI)"_#IPI.
The philosophy behind i-PI is described in the following
publication "(IPI-CPC)"_#IPICPC.
In short, the path integral molecular dynamics is performed by
the Python wrapper, while the client simply computes forces and
energy for each configuration. The communication between the
two components takes place using sockets, and is reduced to the
bare minimum. All the parameters of the dynamics are specified
in the input of i-PI, and all the parameters of the force field
must be specified in the input of LAMMPS, preceding the {fix ipi}
command.
The server address must be specified by the {address} argument,
and can be either the IP address, the fully-qualified name of
the server, or the name of a UNIX socket for local, faster
communication. In the case of internet sockets, the {port}
argument specifies the port number on which i-PI is listening,
while the {unix} optional switch specifies that the socket is a
UNIX socket.
Note that there is no check of data integrity, or that the atomic
configurations make sense. It is assumed that the species in
the i-PI input are listed in the same order as in the data file
of LAMMPS. The initial configuration is ignored, as it will be
substituted with the coordinates received from i-PI before forces
are ever evaluated.
[Restart, fix_modify, output, run start/stop, minimize info:]
There is no restart information associated with this fix, since
all the dynamical parameters are dealt with by i-PI.
[Restrictions:]
Using this fix on anything other than all atoms requires particular
care, since i-PI will know nothing on atoms that are not those
whose coordinates are transferred. However, one could use this
strategy to define an external potential acting on the atoms that
are moved by i-PI.
This fix is part of the USER-MISC package. It is only enabled if LAMMPS
was built with that package. See the "Making
LAMMPS"_Section_start.html#start_3 section for more info.
Because of the use of POSIX sockets, this fix will only work in a
UNIX environment.
[Related commands:]
"fix nve"_fix_nve.html
:line
:link(IPICPC)
[(IPI-CPC)] Ceriotti, More and Manolopoulos,
Comp. Phys. Comm., 185, 1019–1026 (2014)
:link(IPI)
[(IPI)] "http://epfl-cosmo.github.io/gle4md/index.html?page=ipi"_http://epfl-cosmo.github.io/gle4md/index.html?page=ipi
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