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>angle_style hybrid command
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</H3>
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<P><B>Syntax:</B>
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</P>
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<PRE>angle_style hybrid style1 style2 ...
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</PRE>
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<UL><LI>style1,style2 = list of one or more angle styles
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</UL>
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<P><B>Examples:</B>
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</P>
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<PRE>angle_style hybrid harmonic cosine
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angle_coeff 1 harmonic 80.0 1.2
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angle_coeff 2* cosine 50.0
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</PRE>
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<P><B>Description:</B>
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</P>
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<P>The <I>hybrid</I> style enables the use of multiple angle styles in one
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simulation. An angle style is assigned to each angle type. For
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example, angles in a polymer flow (of angle type 1) could be computed
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with a <I>harmonic</I> potential and angles in the wall boundary (of angle
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type 2) could be computed with a <I>cosine</I> potential. The assignment
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of angle type to style is made via the <A HREF = "angle_coeff.html">angle_coeff</A>
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command or in the data file.
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</P>
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<P>In the angle_coeff command, the first coefficient sets the angle style
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and the remaining coefficients are those appropriate to that style.
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2011-06-01 23:21:07 +08:00
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In the example above, the 2 angle_coeff commands set angles of angle
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type 1 to be computed with a <I>harmonic</I> potential with coefficients
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80.0, 1.2 for K, r0. All other angle types (2-N) would be computed
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with a <I>cosine</I> potential with coefficient 50.0 for K.
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2006-09-22 00:22:34 +08:00
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</P>
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2011-06-01 23:21:07 +08:00
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<P>If angle coefficients are specified in the data file read via the
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<A HREF = "read_data.html">read_data</A> command, then the same string,
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e.g. "harmonic" or "cosine", must be listed as the 1st argument of
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each line in the "Angle Coeffs" section, e.g.
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</P>
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<PRE>1 harmonic 80.0 1.2
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</PRE>
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<P>If the angle <I>class2</I> potential is one of the hybrid styles, the same
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rules hold for specifying the additional BondBond and BondAngle
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coefficients either via the input script or in the data file.
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I.e. "class2" must be added in both cases before the "bb" or "ba"
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argument.
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2007-03-21 04:14:06 +08:00
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</P>
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2009-01-06 06:26:31 +08:00
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<P>An angle style of <I>none</I> can be specified as the 2nd argument to the
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2011-06-01 23:21:07 +08:00
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angle_coeff command or the 1st argument in the data file, if you desire
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to turn off certain angle types.
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2006-09-22 00:22:34 +08:00
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</P>
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2007-06-25 22:36:36 +08:00
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<P><B>Restrictions:</B>
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</P>
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<P>This angle style can only be used if LAMMPS was built with the
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"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
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LAMMPS</A> section for more info on packages.
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2006-09-22 00:22:34 +08:00
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</P>
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2008-10-09 22:47:45 +08:00
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<P>Unlike other angle styles, the hybrid angle style does not store angle
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coefficient info for individual sub-styles in a <A HREF = "restart.html">binary restart
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files</A>. Thus when retarting a simulation from a restart
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file, you need to re-specify angle_coeff commands.
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</P>
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2006-09-22 00:22:34 +08:00
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<P><B>Related commands:</B>
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</P>
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<P><A HREF = "angle_coeff.html">angle_coeff</A>
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</P>
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<P><B>Default:</B> none
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</P>
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</HTML>
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