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<div class="section" id="bond-style-hybrid-command">
<span id="index-0"></span><h1>bond_style hybrid command</h1>
<div class="section" id="syntax">
<h2>Syntax</h2>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">bond_style</span> <span class="n">hybrid</span> <span class="n">style1</span> <span class="n">style2</span> <span class="o">...</span>
</pre></div>
</div>
<ul class="simple">
<li>style1,style2 = list of one or more bond styles</li>
</ul>
</div>
<div class="section" id="examples">
<h2>Examples</h2>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">bond_style</span> <span class="n">hybrid</span> <span class="n">harmonic</span> <span class="n">fene</span>
<span class="n">bond_coeff</span> <span class="mi">1</span> <span class="n">harmonic</span> <span class="mf">80.0</span> <span class="mf">1.2</span>
<span class="n">bond_coeff</span> <span class="mi">2</span><span class="o">*</span> <span class="n">fene</span> <span class="mf">30.0</span> <span class="mf">1.5</span> <span class="mf">1.0</span> <span class="mf">1.0</span>
</pre></div>
</div>
</div>
<div class="section" id="description">
<h2>Description</h2>
<p>The <em>hybrid</em> style enables the use of multiple bond styles in one
simulation. A bond style is assigned to each bond type. For example,
bonds in a polymer flow (of bond type 1) could be computed with a
<em>fene</em> potential and bonds in the wall boundary (of bond type 2) could
be computed with a <em>harmonic</em> potential. The assignment of bond type
to style is made via the <a class="reference internal" href="bond_coeff.html"><span class="doc">bond_coeff</span></a> command or in
the data file.</p>
<p>In the bond_coeff commands, the name of a bond style must be added
after the bond type, with the remaining coefficients being those
appropriate to that style. In the example above, the 2 bond_coeff
commands set bonds of bond type 1 to be computed with a <em>harmonic</em>
potential with coefficients 80.0, 1.2 for K, r0. All other bond types
(2-N) are computed with a <em>fene</em> potential with coefficients 30.0,
1.5, 1.0, 1.0 for K, R0, epsilon, sigma.</p>
<p>If bond coefficients are specified in the data file read via the
<a class="reference internal" href="read_data.html"><span class="doc">read_data</span></a> command, then the same rule applies.
E.g. &#8220;harmonic&#8221; or &#8220;fene&#8221; must be added after the bond type, for each
line in the &#8220;Bond Coeffs&#8221; section, e.g.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">Bond</span> <span class="n">Coeffs</span>
</pre></div>
</div>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="mi">1</span> <span class="n">harmonic</span> <span class="mf">80.0</span> <span class="mf">1.2</span>
<span class="mi">2</span> <span class="n">fene</span> <span class="mf">30.0</span> <span class="mf">1.5</span> <span class="mf">1.0</span> <span class="mf">1.0</span>
<span class="o">...</span>
</pre></div>
</div>
<p>A bond style of <em>none</em> with no additional coefficients can be used in
place of a bond style, either in a input script bond_coeff command or
in the data file, if you desire to turn off interactions for specific
bond types.</p>
</div>
<hr class="docutils" />
<div class="section" id="restrictions">
<h2>Restrictions</h2>
<p>This bond style can only be used if LAMMPS was built with the
MOLECULE package (which it is by default). See the <a class="reference internal" href="Section_start.html#start-3"><span class="std std-ref">Making LAMMPS</span></a> section for more info on packages.</p>
<p>Unlike other bond styles, the hybrid bond style does not store bond
coefficient info for individual sub-styles in a <a class="reference internal" href="restart.html"><span class="doc">binary restart files</span></a>. Thus when retarting a simulation from a restart
file, you need to re-specify bond_coeff commands.</p>
</div>
<div class="section" id="related-commands">
<h2>Related commands</h2>
<p><a class="reference internal" href="bond_coeff.html"><span class="doc">bond_coeff</span></a>, <a class="reference internal" href="delete_bonds.html"><span class="doc">delete_bonds</span></a></p>
<p><strong>Default:</strong> none</p>
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