2006-09-22 00:22:34 +08:00
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<CENTER><A HREF = "http://lammps.sandia.gov">LAMMPS WWW Site</A> - <A HREF = "Manual.html">LAMMPS Documentation</A> - <A HREF = "Section_commands.html#comm">LAMMPS Commands</A>
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<HR>
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<H3>fix_modify command
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</H3>
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<P><B>Syntax:</B>
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</P>
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<PRE>fix_modify fix-ID keyword value ...
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</PRE>
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<UL><LI>fix-ID = ID of the fix to modify
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<LI>one or more keyword/value pairs may be appended
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2007-02-10 05:37:30 +08:00
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<LI>keyword = <I>temp</I> or <I>press</I> or <I>thermo</I>
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2006-09-22 00:22:34 +08:00
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2007-02-10 05:37:30 +08:00
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<PRE> <I>temp</I> value = compute ID that calculates a temperature
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<I>press</I> value = compute ID that calculates a pressure
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2006-09-22 00:22:34 +08:00
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<I>thermo</I> value = <I>yes</I> or <I>no</I>
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</PRE>
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</UL>
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<P><B>Examples:</B>
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</P>
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2007-02-10 05:37:30 +08:00
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<PRE>fix_modify 3 temp myTemp press myPress
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fix_modify 1 thermo yes
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2006-09-22 00:22:34 +08:00
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</PRE>
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<P><B>Description:</B>
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</P>
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<P>Modify one or more parameters of a previously defined fix. Not all
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fix styles support all parameters.
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</P>
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<P>The <I>temp</I> keyword is used to determine how a fix computes
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2007-02-10 05:37:30 +08:00
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temperature. The specified compute ID must have been previously
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defined by the user via the <A HREF = "compute.html">compute</A> command and it must
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be a style of compute that calculates a temperature. All fixes that
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compute temperatures defined their own compute by default, as
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described in their documentation. Thus this option allows the user to
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override the default method for computing T.
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2006-09-22 00:22:34 +08:00
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</P>
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2007-02-10 05:37:30 +08:00
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<P>The <I>press</I> keyword is used to determine how a fix computes pressure.
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The specified compute ID must have been previously defined by the user
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via the <A HREF = "compute.html">compute</A> command and it must be a style of
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compute that calculates a pressure. All fixes that compute pressures
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defined their own compute by default, as described in their
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documentation. Thus this option allows the user to override the
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default method for computing P.
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2006-09-22 00:22:34 +08:00
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</P>
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2007-02-10 05:37:30 +08:00
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<P>For fixes that calculates a contribution to the potential energy of
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the system, the <I>thermo</I> keyword will include that contribution in
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thermodyanmic output of the potential energy, as invoked by the
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<A HREF = "thermo_style.html">thermo_style</A> command. The value of the
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contribution can also be printed by itself using the <A HREF = "thermo_style.html">thermo_style
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custom</A> keywords. The documentation for individual
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fix commands specifies whether they make a contribution to the
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potential energy.
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2006-09-22 00:22:34 +08:00
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</P>
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<P><B>Restrictions:</B> none
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</P>
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<P><B>Related commands:</B>
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</P>
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<P><A HREF = "fix.html">fix</A>, <A HREF = "temperature.html">temperature</A>,
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<A HREF = "thermo_style.html">thermo_style</A>
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</P>
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<P><B>Default:</B>
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</P>
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2007-02-10 05:37:30 +08:00
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<P>The option defaults are temp = ID defined by fix, press = ID defined
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by fix, thermo = no.
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2006-09-22 00:22:34 +08:00
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</P>
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</HTML>
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