2006-09-22 00:22:34 +08:00
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"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
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:link(lws,http://lammps.sandia.gov)
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:link(ld,Manual.html)
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:link(lc,Section_commands.html#comm)
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:line
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fix efield command :h3
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[Syntax:]
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fix ID group-ID efield ex ey ez :pre
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ID, group-ID are documented in "fix"_fix.html command
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efield = style name of this fix command
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2010-04-22 06:47:54 +08:00
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ex,ey,ez = E-field component values (electric field units)
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any of ex,ey,ez can be a variable (see below) :ul
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2006-09-22 00:22:34 +08:00
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[Examples:]
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2010-04-22 06:47:54 +08:00
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fix kick external-field efield 1.0 0.0 0.0
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fix kick external-field efield 0.0 0.0 v_oscillate :pre
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2006-09-22 00:22:34 +08:00
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[Description:]
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Add a force F = qE to each charged atom in the group due to an
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external electric field being applied to the system.
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2010-04-22 06:47:54 +08:00
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Any of the 3 quantities defining the E-field components can be
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2010-04-27 22:33:02 +08:00
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specified as an equal-style or atom-style "variable"_variable.html,
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namely {ex}, {ey}, {ez}. If the value is a variable, it should be
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specified as v_ID, where ID is the variable ID. In this case, the
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variable will be evaluated each timestep, and its value used to
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determine the E-field component.
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2010-04-22 06:47:54 +08:00
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Equal-style variables can specify formulas with various mathematical
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functions, and include "thermo_style"_thermo_style.html command
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keywords for the simulation box parameters and timestep and elapsed
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time. Thus it is easy to specify a time-dependent E-field.
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Atom-style variables can specify the same formulas as equal-style
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variables but can also include per-atom values, such as atom
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coordinates. Thus it is easy to specify a spatially-dependent E-field
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with optional time-dependence as well.
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2007-10-11 06:28:11 +08:00
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[Restart, fix_modify, output, run start/stop, minimize info:]
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2007-06-26 08:03:39 +08:00
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No information about this fix is written to "binary restart
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files"_restart.html. None of the "fix_modify"_fix_modify.html options
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2010-04-03 00:51:06 +08:00
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are relevant to this fix. No global or per-atom quantities are stored
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by this fix for access by various "output
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2007-10-11 06:28:11 +08:00
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commands"_Section_howto.html#4_15. No parameter of this fix can be
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used with the {start/stop} keywords of the "run"_run.html command.
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This fix is not invoked during "energy minimization"_minimize.html.
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2007-06-26 08:03:39 +08:00
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2006-09-22 00:22:34 +08:00
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[Restrictions:] none
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[Related commands:]
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"fix addforce"_fix_addforce.html
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[Default:] none
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